Advisories for Golang/Github.com/Traefik/Traefik package

2026

Traefik: Gateway API TraefikService backend accepts rest@internal, allowing unauthorized exposure of the REST provider despite providers.rest.insecure=false

There is a medium severity vulnerability in Traefik's Kubernetes Gateway API provider that allows a tenant with HTTPRoute creation permissions to expose the REST provider handler, bypassing the providers.rest.insecure=false setting. The Gateway provider accepts any TraefikService backend reference whose name ends with @internal, making it possible to route traffic to rest@internal in addition to the intended api@internal. In shared Gateway deployments where the REST provider is enabled, this allows a …

Traefik: Gateway API TraefikService backend accepts rest@internal, allowing unauthorized exposure of the REST provider despite providers.rest.insecure=false

There is a medium severity vulnerability in Traefik's Kubernetes Gateway API provider that allows a tenant with HTTPRoute creation permissions to expose the REST provider handler, bypassing the providers.rest.insecure=false setting. The Gateway provider accepts any TraefikService backend reference whose name ends with @internal, making it possible to route traffic to rest@internal in addition to the intended api@internal. In shared Gateway deployments where the REST provider is enabled, this allows a …

Traefik: Gateway API TraefikService backend accepts rest@internal, allowing unauthorized exposure of the REST provider despite providers.rest.insecure=false

There is a medium severity vulnerability in Traefik's Kubernetes Gateway API provider that allows a tenant with HTTPRoute creation permissions to expose the REST provider handler, bypassing the providers.rest.insecure=false setting. The Gateway provider accepts any TraefikService backend reference whose name ends with @internal, making it possible to route traffic to rest@internal in addition to the intended api@internal. In shared Gateway deployments where the REST provider is enabled, this allows a …

Traefik's errors middleware forwards Authorization and Cookie headers to separate error page service

There is a medium severity information disclosure vulnerability in Traefik's errors (custom error pages) middleware. When the backend returns a response matching the configured status range, the middleware forwards the original request's complete header set, including Authorization, Cookie, and other authentication material, to the separate error page service rather than only the minimal context needed to render the error page. This behavior is undocumented: the documentation states only that Host …

Traefik's errors middleware forwards Authorization and Cookie headers to separate error page service

There is a medium severity information disclosure vulnerability in Traefik's errors (custom error pages) middleware. When the backend returns a response matching the configured status range, the middleware forwards the original request's complete header set, including Authorization, Cookie, and other authentication material, to the separate error page service rather than only the minimal context needed to render the error page. This behavior is undocumented: the documentation states only that Host …

Traefik's ForwardAuth trustForwardHeader=false allows spoofed X-Forwarded-Prefix to bypass authentication

There is a high-severity authentication bypass vulnerability in Traefik's ForwardAuth middleware when trustForwardHeader=false is configured and Traefik is deployed behind a trusted upstream proxy. While X-Forwarded-* headers (such as X-Forwarded-For, X-Forwarded-Host, and X-Forwarded-Proto) from trusted context are correctly rebuilt, it does not strip or rebuild X-Forwarded-Prefix, leaving any attacker-supplied value intact in the subrequest forwarded to the authentication service. When the authentication service makes authorization decisions based on X-Forwarded-Prefix, an …

Traefik's ForwardAuth trustForwardHeader=false allows spoofed X-Forwarded-Prefix to bypass authentication

There is a high-severity authentication bypass vulnerability in Traefik's ForwardAuth middleware when trustForwardHeader=false is configured and Traefik is deployed behind a trusted upstream proxy. While X-Forwarded-* headers (such as X-Forwarded-For, X-Forwarded-Host, and X-Forwarded-Proto) from trusted context are correctly rebuilt, it does not strip or rebuild X-Forwarded-Prefix, leaving any attacker-supplied value intact in the subrequest forwarded to the authentication service. When the authentication service makes authorization decisions based on X-Forwarded-Prefix, an …

Traefik's ForwardAuth trustForwardHeader=false allows spoofed X-Forwarded-Prefix to bypass authentication

There is a high-severity authentication bypass vulnerability in Traefik's ForwardAuth middleware when trustForwardHeader=false is configured and Traefik is deployed behind a trusted upstream proxy. While X-Forwarded-* headers (such as X-Forwarded-For, X-Forwarded-Host, and X-Forwarded-Proto) from trusted context are correctly rebuilt, it does not strip or rebuild X-Forwarded-Prefix, leaving any attacker-supplied value intact in the subrequest forwarded to the authentication service. When the authentication service makes authorization decisions based on X-Forwarded-Prefix, an …

Traefik: Pre-authentication decision bypass due to forwarded alias spoofing

There is a high severity authentication bypass vulnerability in Traefik's ForwardAuth and snippet-based authentication middleware. Traefik's forwarded-header sanitization logic targets only canonical header names (e.g., X-Forwarded-Proto) and does not strip or normalize alias variants that use underscores instead of dashes (e.g., X_Forwarded_Proto). These unsanitized alias headers are forwarded intact to the authentication backend. When the backend normalizes underscore and dash header forms equivalently, an attacker can inject spoofed trust context …

Traefik: Pre-authentication decision bypass due to forwarded alias spoofing

There is a high severity authentication bypass vulnerability in Traefik's ForwardAuth and snippet-based authentication middleware. Traefik's forwarded-header sanitization logic targets only canonical header names (e.g., X-Forwarded-Proto) and does not strip or normalize alias variants that use underscores instead of dashes (e.g., X_Forwarded_Proto). These unsanitized alias headers are forwarded intact to the authentication backend. When the backend normalizes underscore and dash header forms equivalently, an attacker can inject spoofed trust context …

Traefik: Pre-authentication decision bypass due to forwarded alias spoofing

There is a high severity authentication bypass vulnerability in Traefik's ForwardAuth and snippet-based authentication middleware. Traefik's forwarded-header sanitization logic targets only canonical header names (e.g., X-Forwarded-Proto) and does not strip or normalize alias variants that use underscores instead of dashes (e.g., X_Forwarded_Proto). These unsanitized alias headers are forwarded intact to the authentication backend. When the backend normalizes underscore and dash header forms equivalently, an attacker can inject spoofed trust context …

Traefik: A timing side-channel vulnerability allows for valid username enumeration via BasicAuth middleware

There is a timing side-channel vulnerability in Traefik's BasicAuth middleware that allows an attacker to enumerate valid usernames through response-time differences. The variable intended to hold a constant-time fallback secret always resolves to an empty string, causing the constant-time comparison to short-circuit in microseconds rather than performing a full bcrypt evaluation. This restores the original timing oracle and makes it possible to distinguish existing users from non-existing ones by measuring …

Traefik: A timing side-channel vulnerability allows for valid username enumeration via BasicAuth middleware

There is a timing side-channel vulnerability in Traefik's BasicAuth middleware that allows an attacker to enumerate valid usernames through response-time differences. The variable intended to hold a constant-time fallback secret always resolves to an empty string, causing the constant-time comparison to short-circuit in microseconds rather than performing a full bcrypt evaluation. This restores the original timing oracle and makes it possible to distinguish existing users from non-existing ones by measuring …

Traefik: A timing side-channel vulnerability allows for valid username enumeration via BasicAuth middleware

There is a timing side-channel vulnerability in Traefik's BasicAuth middleware that allows an attacker to enumerate valid usernames through response-time differences. The variable intended to hold a constant-time fallback secret always resolves to an empty string, causing the constant-time comparison to short-circuit in microseconds rather than performing a full bcrypt evaluation. This restores the original timing oracle and makes it possible to distinguish existing users from non-existing ones by measuring …

Traefik Kubernetes CRD allows unauthorized cross-namespace middleware binding

There is a vulnerability in Traefik's Kubernetes CRD provider cross-namespace isolation enforcement. When providers.kubernetesCRD.allowCrossNamespace=false, Traefik correctly rejects direct cross-namespace middleware references from IngressRoute objects, but fails to apply the same restriction to middleware references nested inside a Chain middleware's spec.chain.middlewares[]. An actor with permission to create or update Traefik CRDs in their own namespace can exploit this to cause Traefik to resolve and apply middleware objects from another namespace, bypassing …

Traefik Kubernetes CRD allows unauthorized cross-namespace middleware binding

There is a vulnerability in Traefik's Kubernetes CRD provider cross-namespace isolation enforcement. When providers.kubernetesCRD.allowCrossNamespace=false, Traefik correctly rejects direct cross-namespace middleware references from IngressRoute objects, but fails to apply the same restriction to middleware references nested inside a Chain middleware's spec.chain.middlewares[]. An actor with permission to create or update Traefik CRDs in their own namespace can exploit this to cause Traefik to resolve and apply middleware objects from another namespace, bypassing …

Traefik Kubernetes CRD allows unauthorized cross-namespace middleware binding

There is a vulnerability in Traefik's Kubernetes CRD provider cross-namespace isolation enforcement. When providers.kubernetesCRD.allowCrossNamespace=false, Traefik correctly rejects direct cross-namespace middleware references from IngressRoute objects, but fails to apply the same restriction to middleware references nested inside a Chain middleware's spec.chain.middlewares[]. An actor with permission to create or update Traefik CRDs in their own namespace can exploit this to cause Traefik to resolve and apply middleware objects from another namespace, bypassing …

Traefik has an StripPrefixRegex Middleware Authorization Bypass via Path/RawPath Desync

There is a high severity authentication bypass vulnerability in Traefik's StripPrefixRegex middleware when used in combination with ForwardAuth, BasicAuth, or DigestAuth. The middleware matches the regex against the decoded URL path but uses the resulting byte length to slice the percent-encoded raw path. When a dot (or multiple dots) appears in the prefix portion of the URL, the raw path after stripping becomes a dot-segment (e.g. /./admin/secret). ForwardAuth receives this …

Traefik has an StripPrefixRegex Middleware Authorization Bypass via Path/RawPath Desync

There is a high severity authentication bypass vulnerability in Traefik's StripPrefixRegex middleware when used in combination with ForwardAuth, BasicAuth, or DigestAuth. The middleware matches the regex against the decoded URL path but uses the resulting byte length to slice the percent-encoded raw path. When a dot (or multiple dots) appears in the prefix portion of the URL, the raw path after stripping becomes a dot-segment (e.g. /./admin/secret). ForwardAuth receives this …

Traefik has an StripPrefixRegex Middleware Authorization Bypass via Path/RawPath Desync

There is a high severity authentication bypass vulnerability in Traefik's StripPrefixRegex middleware when used in combination with ForwardAuth, BasicAuth, or DigestAuth. The middleware matches the regex against the decoded URL path but uses the resulting byte length to slice the percent-encoded raw path. When a dot (or multiple dots) appears in the prefix portion of the URL, the raw path after stripping becomes a dot-segment (e.g. /./admin/secret). ForwardAuth receives this …

Traefik: Deny Rule Bypass via Unauthenticated Malicious gRPC Requests in gRPC-Go Dependency (CVE-2026-33186)

There is a potential vulnerability in Traefik due to its dependency on an affected version of gRPC-Go (CVE-2026-33186). A remote, unauthenticated attacker can send gRPC requests with a malformed HTTP/2 :path pseudo-header omitting the mandatory leading slash (e.g., Service/Method instead of /Service/Method). While the server routes such requests correctly, path-based authorization interceptors evaluate the raw non-canonical path and fail to match "deny" rules, allowing the request to bypass the policy …

Traefik: Deny Rule Bypass via Unauthenticated Malicious gRPC Requests in gRPC-Go Dependency (CVE-2026-33186)

There is a potential vulnerability in Traefik due to its dependency on an affected version of gRPC-Go (CVE-2026-33186). A remote, unauthenticated attacker can send gRPC requests with a malformed HTTP/2 :path pseudo-header omitting the mandatory leading slash (e.g., Service/Method instead of /Service/Method). While the server routes such requests correctly, path-based authorization interceptors evaluate the raw non-canonical path and fail to match "deny" rules, allowing the request to bypass the policy …

Traefik Vulnerable to BasicAuth/DigestAuth Identity Spoofing via Non-Canonical headerField

There is a potential vulnerability in Traefik's Basic and Digest authentication middlewares when headerField is configured with a non-canonical HTTP header name. An authenticated attacker with valid credentials can inject the canonical version of the configured header to impersonate any identity to the backend. Because Traefik writes the authenticated username using a non-canonical map key, it creates a separate header entry rather than overwriting the attacker's canonical one — causing …

Traefik Vulnerable to BasicAuth/DigestAuth Identity Spoofing via Non-Canonical headerField

There is a potential vulnerability in Traefik's Basic and Digest authentication middlewares when headerField is configured with a non-canonical HTTP header name. An authenticated attacker with valid credentials can inject the canonical version of the configured header to impersonate any identity to the backend. Because Traefik writes the authenticated username using a non-canonical map key, it creates a separate header entry rather than overwriting the attacker's canonical one — causing …

Traefik has Knative Ingress Rule Injection that Allows Host Restriction Bypass

There is a potential vulnerability in Traefik's Kubernetes Knative, Ingress, and Ingress-NGINX providers related to rule injection. User-controlled values are interpolated into backtick-delimited Traefik router rule expressions without escaping or validation. A malicious value containing a backtick can terminate the literal and inject additional operators into Traefik's rule language, altering the parsed rule tree. In shared or multi-tenant deployments, this can bypass host and header routing constraints and redirect unauthorized …

Traefik has Knative Ingress Rule Injection that Allows Host Restriction Bypass

There is a potential vulnerability in Traefik's Kubernetes Knative, Ingress, and Ingress-NGINX providers related to rule injection. User-controlled values are interpolated into backtick-delimited Traefik router rule expressions without escaping or validation. A malicious value containing a backtick can terminate the literal and inject additional operators into Traefik's rule language, altering the parsed rule tree. In shared or multi-tenant deployments, this can bypass host and header routing constraints and redirect unauthorized …

Traefik has a Potential mTLS Bypass via Fragmented TLS ClientHello Causing Pre-SNI Sniff Fallback to Default Non-mTLS TLS Config

There is a potential vulnerability in Traefik's TLS SNI pre-sniffing logic related to fragmented ClientHello packets. When a TLS ClientHello is fragmented across multiple records, Traefik's SNI extraction may fail with an EOF and return an empty SNI. The TCP router then falls back to the default TLS configuration, which does not require client certificates by default. This allows an attacker to bypass route-level mTLS enforcement and access services that …

Traefik has a Potential mTLS Bypass via Fragmented TLS ClientHello Causing Pre-SNI Sniff Fallback to Default Non-mTLS TLS Config

There is a potential vulnerability in Traefik's TLS SNI pre-sniffing logic related to fragmented ClientHello packets. When a TLS ClientHello is fragmented across multiple records, Traefik's SNI extraction may fail with an EOF and return an empty SNI. The TCP router then falls back to the default TLS configuration, which does not require client certificates by default. This allows an attacker to bypass route-level mTLS enforcement and access services that …

Traefik has a Potential mTLS Bypass via Fragmented TLS ClientHello Causing Pre-SNI Sniff Fallback to Default Non-mTLS TLS Config

There is a potential vulnerability in Traefik's TLS SNI pre-sniffing logic related to fragmented ClientHello packets. When a TLS ClientHello is fragmented across multiple records, Traefik's SNI extraction may fail with an EOF and return an empty SNI. The TCP router then falls back to the default TLS configuration, which does not require client certificates by default. This allows an attacker to bypass route-level mTLS enforcement and access services that …

Traefik Affected by BasicAuth Middleware Timing Attack Allows Username Enumeration

There is a potential vulnerability in Traefik's BasicAuth middleware that allows username enumeration via a timing attack. When a submitted username exists, the middleware performs a bcrypt password comparison taking ~166ms. When the username does not exist, the response returns immediately in ~0.6ms. This ~298x timing difference is observable over the network and allows an unauthenticated attacker to reliably distinguish valid from invalid usernames. A timing attack vulnerability exists in …

Traefik Affected by BasicAuth Middleware Timing Attack Allows Username Enumeration

There is a potential vulnerability in Traefik's BasicAuth middleware that allows username enumeration via a timing attack. When a submitted username exists, the middleware performs a bcrypt password comparison taking ~166ms. When the username does not exist, the response returns immediately in ~0.6ms. This ~298x timing difference is observable over the network and allows an unauthenticated attacker to reliably distinguish valid from invalid usernames. A timing attack vulnerability exists in …

Traefik Affected by BasicAuth Middleware Timing Attack Allows Username Enumeration

There is a potential vulnerability in Traefik's BasicAuth middleware that allows username enumeration via a timing attack. When a submitted username exists, the middleware performs a bcrypt password comparison taking ~166ms. When the username does not exist, the response returns immediately in ~0.6ms. This ~298x timing difference is observable over the network and allows an unauthenticated attacker to reliably distinguish valid from invalid usernames. A timing attack vulnerability exists in …

Traefik: kubernetes gateway rule injection via unescaped backticks in HTTPRoute match values

There is a potential vulnerability in Traefik's Kubernetes Gateway provider related to rule injection. A tenant with write access to an HTTPRoute resource can inject backtick-delimited rule tokens into Traefik's router rule language via unsanitized header or query parameter match values. In shared gateway deployments, this can bypass listener hostname constraints and redirect traffic for victim hostnames to attacker-controlled backends.

Traefik: kubernetes gateway rule injection via unescaped backticks in HTTPRoute match values

There is a potential vulnerability in Traefik's Kubernetes Gateway provider related to rule injection. A tenant with write access to an HTTPRoute resource can inject backtick-delimited rule tokens into Traefik's router rule language via unsanitized header or query parameter match values. In shared gateway deployments, this can bypass listener hostname constraints and redirect traffic for victim hostnames to attacker-controlled backends.

Traefik: kubernetes gateway rule injection via unescaped backticks in HTTPRoute match values

There is a potential vulnerability in Traefik's Kubernetes Gateway provider related to rule injection. A tenant with write access to an HTTPRoute resource can inject backtick-delimited rule tokens into Traefik's router rule language via unsanitized header or query parameter match values. In shared gateway deployments, this can bypass listener hostname constraints and redirect traffic for victim hostnames to attacker-controlled backends.

Traefik: tcp router clears read deadlines before tls forwarding, enabling stalled handshakes (Slowloris DOS)

There is a potential vulnerability in Traefik managing TLS handshake on TCP routers. When Traefik processes a TLS connection on a TCP router, the read deadline used to bound protocol sniffing is cleared before the TLS handshake is completed. When a TLS handshake read error occurs, the code attempts a second handshake with different connection parameters, silently ignoring the initial error. A remote unauthenticated client can exploit this by sending …

Traefik: tcp router clears read deadlines before tls forwarding, enabling stalled handshakes (Slowloris DOS)

There is a potential vulnerability in Traefik managing TLS handshake on TCP routers. When Traefik processes a TLS connection on a TCP router, the read deadline used to bound protocol sniffing is cleared before the TLS handshake is completed. When a TLS handshake read error occurs, the code attempts a second handshake with different connection parameters, silently ignoring the initial error. A remote unauthenticated client can exploit this by sending …

Traefik has unbounded io.ReadAll on auth server response body that causes OOM DOS

The ForwardAuth middleware reads the entire authentication server response body into memory using io.ReadAll with no size limit. A single HTTP request through a ForwardAuth-protected route can cause the Traefik process to allocate gigabytes of memory and be killed by the OOM killer, resulting in complete denial of service for all routes on the affected entrypoint.

Traefik has unbounded io.ReadAll on auth server response body that causes OOM DOS

The ForwardAuth middleware reads the entire authentication server response body into memory using io.ReadAll with no size limit. A single HTTP request through a ForwardAuth-protected route can cause the Traefik process to allocate gigabytes of memory and be killed by the OOM killer, resulting in complete denial of service for all routes on the affected entrypoint.

traefik CVE-2024-45410 fix bypass: lowercase `Connection` tokens can delete traefik-managed forwarded identity headers (for example, `X-Real-Ip`)

There is a potential vulnerability in Traefik managing the Connection header with X-Forwarded headers. When Traefik processes HTTP/1.1 requests, the protection put in place to prevent the removal of Traefik-managed X-Forwarded headers (such as X-Real-Ip, X-Forwarded-Host, X-Forwarded-Port, etc.) via the Connection header does not handle case sensitivity correctly. The Connection tokens are compared case-sensitively against the protected header names, but the actual header deletion operates case-insensitively. As a result, a …

traefik CVE-2024-45410 fix bypass: lowercase `Connection` tokens can delete traefik-managed forwarded identity headers (for example, `X-Real-Ip`)

There is a potential vulnerability in Traefik managing the Connection header with X-Forwarded headers. When Traefik processes HTTP/1.1 requests, the protection put in place to prevent the removal of Traefik-managed X-Forwarded headers (such as X-Real-Ip, X-Forwarded-Host, X-Forwarded-Port, etc.) via the Connection header does not handle case sensitivity correctly. The Connection tokens are compared case-sensitively against the protected header names, but the actual header deletion operates case-insensitively. As a result, a …

Traefik: TCP readTimeout bypass via STARTTLS on Postgres

A remote, unauthenticated client can bypass Traefik entrypoint respondingTimeouts.readTimeout by sending the 8-byte Postgres SSLRequest (STARTTLS) prelude and then stalling, causing connections to remain open indefinitely and enabling file-descriptor and goroutine exhaustion denial of service. This triggers during protocol detection before routing, so it is reachable on an entrypoint even when no Postgres/TCP routers are configured (the PoC uses only an HTTP router).

Traefik's ACME TLS-ALPN fast path lacks timeouts and close on handshake stall

Affected code: pkg/server/router/tcp/router.go (ACME TLS-ALPN handling). When a ClientHello advertises acme-tls/1, Traefik intercepts it and calls tls.Server(…).Handshake() without any read/write deadlines and without closing the connection afterward. Immediately before this branch, existing deadlines set by the entrypoint are cleared. A client that sends the ALPN marker and then stops responding can keep the goroutine and socket open indefinitely, potentially exhausting the entrypoint under load. Exposure is limited to entrypoints where …

Traefik's ACME TLS-ALPN fast path lacks timeouts and close on handshake stall

Affected code: pkg/server/router/tcp/router.go (ACME TLS-ALPN handling). When a ClientHello advertises acme-tls/1, Traefik intercepts it and calls tls.Server(…).Handshake() without any read/write deadlines and without closing the connection afterward. Immediately before this branch, existing deadlines set by the entrypoint are cleared. A client that sends the ALPN marker and then stops responding can keep the goroutine and socket open indefinitely, potentially exhausting the entrypoint under load. Exposure is limited to entrypoints where …

2025

Traefik Inverted TLS Verification Logic in ingress-nginx Provider

A logic error in Traefik's experimental ingress-nginx provider inverts the semantics of the nginx.ingress.kubernetes.io/proxy-ssl-verify annotation. Setting the annotation to "on" (intending to enable backend TLS certificate verification) actually disables verification, allowing man-in-the-middle attacks against HTTPS backends when operators believe they are protected.

Path Normalization Bypass in Traefik Router + Middleware Rules

There is a potential vulnerability in Traefik managing the requests using a PathPrefix, Path or PathRegex matcher. When Traefik is configured to route the requests to a backend using a matcher based on the path; if the request path contains an encoded restricted character from the following set ('/', '', 'Null', ';', '?', '#'), it’s possible to target a backend, exposed using another router, by-passing the middlewares chain. Access Control …

Path Normalization Bypass in Traefik Router + Middleware Rules

There is a potential vulnerability in Traefik managing the requests using a PathPrefix, Path or PathRegex matcher. When Traefik is configured to route the requests to a backend using a matcher based on the path; if the request path contains an encoded restricted character from the following set ('/', '', 'Null', ';', '?', '#'), it’s possible to target a backend, exposed using another router, by-passing the middlewares chain. Access Control …

Path Normalization Bypass in Traefik Router + Middleware Rules

There is a potential vulnerability in Traefik managing the requests using a PathPrefix, Path or PathRegex matcher. When Traefik is configured to route the requests to a backend using a matcher based on the path; if the request path contains an encoded restricted character from the following set ('/', '', 'Null', ';', '?', '#'), it’s possible to target a backend, exposed using another router, by-passing the middlewares chain. Access Control …

Traefik Client Plugin's Path Traversal Vulnerability Allows Arbitrary File Overwrite and Remote Code Execution

A path traversal vulnerability was discovered in WASM Traefik’s plugin installation mechanism. By supplying a maliciously crafted ZIP archive containing file paths with ../ sequences, an attacker can overwrite arbitrary files on the system outside of the intended plugin directory. This can lead to remote code execution (RCE), privilege escalation, persistence, or denial of service. ✅ After investigation, it is confirmed that no plugins on the Catalog were affected. There …

Traefik Client Plugin's Path Traversal Vulnerability Allows Arbitrary File Overwrite and Remote Code Execution

A path traversal vulnerability was discovered in WASM Traefik’s plugin installation mechanism. By supplying a maliciously crafted ZIP archive containing file paths with ../ sequences, an attacker can overwrite arbitrary files on the system outside of the intended plugin directory. This can lead to remote code execution (RCE), privilege escalation, persistence, or denial of service. ✅ After investigation, it is confirmed that no plugins on the Catalog were affected. There …

Traefik affected by Go HTTP Request Smuggling Vulnerability

net/http: request smuggling through invalid chunked data: The net/http package accepts data in the chunked transfer encoding containing an invalid chunk-size line terminated by a bare LF. When used in conjunction with a server or proxy which incorrectly interprets a bare LF in a chunk extension as part of the extension, this could permit request smuggling. [CVE-2025-22871] Vendor Affected Components: Go: 1.23.x < 1.23.8 More Details: CVE-2025-22871

Traefik affected by Go HTTP Request Smuggling Vulnerability

net/http: request smuggling through invalid chunked data: The net/http package accepts data in the chunked transfer encoding containing an invalid chunk-size line terminated by a bare LF. When used in conjunction with a server or proxy which incorrectly interprets a bare LF in a chunk extension as part of the extension, this could permit request smuggling. [CVE-2025-22871] Vendor Affected Components: Go: 1.23.x < 1.23.8 More Details: CVE-2025-22871

2024

HTTP client can manipulate custom HTTP headers that are added by Traefik

When a HTTP request is processed by Traefik, certain HTTP headers such as X-Forwarded-Host or X-Forwarded-Port are added by Traefik before the request is routed to the application. For a HTTP client, it should not be possible to remove or modify these headers. Since the application trusts the value of these headers, security implications might arise, if they can be modified. For HTTP/1.1, however, it was found that some of …

HTTP client can manipulate custom HTTP headers that are added by Traefik

When a HTTP request is processed by Traefik, certain HTTP headers such as X-Forwarded-Host or X-Forwarded-Port are added by Traefik before the request is routed to the application. For a HTTP client, it should not be possible to remove or modify these headers. Since the application trusts the value of these headers, security implications might arise, if they can be modified. For HTTP/1.1, however, it was found that some of …

HTTP client can manipulate custom HTTP headers that are added by Traefik

When a HTTP request is processed by Traefik, certain HTTP headers such as X-Forwarded-Host or X-Forwarded-Port are added by Traefik before the request is routed to the application. For a HTTP client, it should not be possible to remove or modify these headers. Since the application trusts the value of these headers, security implications might arise, if they can be modified. For HTTP/1.1, however, it was found that some of …

2023

Uncontrolled Resource Consumption

Traefik is an open source HTTP reverse proxy and load balancer. The traefik docker container uses 100% CPU when it serves as its own backend, which is an automatically generated route resulting from the Docker integration in the default configuration. This issue has been addressed in versions 2.10.6 and 3.0.0-beta5. Users are advised to upgrade. There are no known workarounds for this vulnerability.

Uncontrolled Resource Consumption

Traefik is an open source HTTP reverse proxy and load balancer. The traefik docker container uses 100% CPU when it serves as its own backend, which is an automatically generated route resulting from the Docker integration in the default configuration. This issue has been addressed in versions 2.10.6 and 3.0.0-beta5. Users are advised to upgrade. There are no known workarounds for this vulnerability.

Improper Input Validation

Traefik is an open source HTTP reverse proxy and load balancer. When a request is sent to Traefik with a URL fragment, Traefik automatically URL encodes and forwards the fragment to the backend server. This violates RFC 7230 because in the origin-form the URL should only contain the absolute path and the query. When this is combined with another frontend proxy like Nginx, it can be used to bypass frontend …

Improper Input Validation

Traefik is an open source HTTP reverse proxy and load balancer. When a request is sent to Traefik with a URL fragment, Traefik automatically URL encodes and forwards the fragment to the backend server. This violates RFC 7230 because in the origin-form the URL should only contain the absolute path and the query. When this is combined with another frontend proxy like Nginx, it can be used to bypass frontend …

2022

Traefik HTTP/2 connections management could cause a denial of service

Impact There is a potential vulnerability in Traefik managing HTTP/2 connections. A closing HTTP/2 server connection could hang forever because of a subsequent fatal error. This failure mode could be exploited to cause a denial of service. Patches Traefik v2.8.x: https://github.com/traefik/traefik/releases/tag/v2.8.8 Traefik v2.9.x: https://github.com/traefik/traefik/releases/tag/v2.9.0-rc5 Workarounds No workaround. For more information If you have any questions or comments about this advisory, please open an issue.

Insufficiently Protected Credentials

types/types.go in Containous Traefik 1.7.x through 1.7.11, when the –api flag is used and the API is publicly reachable and exposed without sufficient access control (which is contrary to the API documentation), allows remote authenticated users to discover password hashes by reading the Basic HTTP Authentication or Digest HTTP Authentication section, or discover a key by reading the ClientTLS section. These can be found in the JSON response to a …

Insufficiently Protected Credentials

types/types.go in Containous Traefik 1.7.x through 1.7.11, when the –api flag is used and the API is publicly reachable and exposed without sufficient access control (which is contrary to the API documentation), allows remote authenticated users to discover password hashes by reading the Basic HTTP Authentication or Digest HTTP Authentication section, or discover a key by reading the ClientTLS section. These can be found in the JSON response to a …

Improper Certificate Validation

Traefik is an HTTP reverse proxy and load balancer., Traefik skips the router transport layer security (TLS) configuration when the host header is a fully qualified domain name (FQDN). For a request, the TLS configuration choice can be different than the router choice, which implies the use of a wrong TLS configuration. When sending a request using FQDN handled by a router configured with a dedicated TLS configuration, the TLS …

URL Redirection to Untrusted Site ('Open Redirect')

In Traefik before versions 1.7.26, 2.2.8, and 2.3.0-rc3, there exists a potential open redirect vulnerability in Traefik's handling of the "X-Forwarded-Prefix" header. The Traefik API dashboard component does not validate that the value of the header "X-Forwarded-Prefix" is a site relative path and will redirect to any header provided URI. Successful exploitation of an open redirect can be used to entice victims to disclose sensitive information. Active Exploitation of this …

URL Redirection to Untrusted Site ('Open Redirect')

In Traefik before versions 1.7.26, 2.2.8, and 2.3.0-rc3, there exists a potential open redirect vulnerability in Traefik's handling of the "X-Forwarded-Prefix" header. The Traefik API dashboard component doesn't validate that the value of the header "X-Forwarded-Prefix" is a site relative path and will redirect to any header provided URI. Successful exploitation of an open redirect can be used to entice victims to disclose sensitive information. Active Exploitation of this issue …

URL Redirection to Untrusted Site ('Open Redirect')

In Traefik before versions 1.7.26, 2.2.8, and 2.3.0-rc3, there exists a potential open redirect vulnerability in Traefik's handling of the "X-Forwarded-Prefix" header. The Traefik API dashboard component doesn't validate that the value of the header "X-Forwarded-Prefix" is a site relative path and will redirect to any header provided URI. Successful exploitation of an open redirect can be used to entice victims to disclose sensitive information. Active Exploitation of this issue …

URL Redirection to Untrusted Site ('Open Redirect')

In Traefik before versions 1.7.26, 2.2.8, and 2.3.0-rc3, there exists a potential open redirect vulnerability in Traefik's handling of the "X-Forwarded-Prefix" header. The Traefik API dashboard component does not validate that the value of the header "X-Forwarded-Prefix" is a site relative path and will redirect to any header provided URI. Successful exploitation of an open redirect can be used to entice victims to disclose sensitive information. Active Exploitation of this …

2021

Improper Control of Dynamically-Managed Code Resources

Traefik is an HTTP reverse proxy and load balancer. Prior to version 2.4.13, there exists a potential header vulnerability in Traefik's handling of the Connection header. Active exploitation of this issue is unlikely, as it requires that a removed header would lead to a privilege escalation, however, the Traefik team has addressed this issue to prevent any potential abuse. If one has a chain of Traefik middlewares, and one of …

Improper Control of Dynamically-Managed Code Resources

Traefik is an HTTP reverse proxy and load balancer. Prior to version 2.4.13, there exists a potential header vulnerability in Traefik's handling of the Connection header. Active exploitation of this issue is unlikely, as it requires that a removed header would lead to a privilege escalation, however, the Traefik team has addressed this issue to prevent any potential abuse. If one has a chain of Traefik middlewares, and one of …