Advisories for Golang/Github.com/Gofiber/Fiber package

The helmet middleware in gofiber/fiber never sets the Strict-Transport-Security (HSTS) response header, even when HSTSMaxAge is explicitly configured, because the condition check at helmet.go:67 uses c.Protocol() — which returns the HTTP protocol version string (e.g., "HTTP/1.1", "HTTP/2.0") — instead of c.Scheme() — which returns the URL scheme ("http" or "https"). Since c.Protocol() never equals "https" in any real deployment, the HSTS header is permanently disabled, defeating the security protection.

The BalancerForward proxy helper in GoFiber uses Header.Add() instead of Header.Set() when injecting the X-Real-IP header. This appends the real client IP as a second header value rather than replacing any attacker-supplied value. Upstream servers that read the first X-Real-IP header (nginx, Express, most HTTP servers) use the attacker's spoofed IP for logging, rate limiting, and access control.

The BalancerForward proxy helper in GoFiber uses Header.Add() instead of Header.Set() when injecting the X-Real-IP header. This appends the real client IP as a second header value rather than replacing any attacker-supplied value. Upstream servers that read the first X-Real-IP header (nginx, Express, most HTTP servers) use the attacker's spoofed IP for logging, rate limiting, and access control.

The default Authorizer function in GoFiber's BasicAuth middleware uses short-circuit evaluation that skips password hash comparison for non-existent usernames. With bcrypt-hashed passwords (the primary use case), the timing difference between a valid and invalid username is approximately 1,000,000:1 (~100ms vs ~100ns), enabling reliable remote username enumeration.

Description A Cross-Site Scripting (CWE-79) vulnerability in Go Fiber allows a remote attacker to inject arbitrary HTML/JavaScript by supplying Accept: text/html on any request whose handler passes attacker-influenced data to the AutoFormat() feature. This affects github.com/gofiber/fiber/v3 (DefaultRes.AutoFormat) through version 3.1.0 and github.com/gofiber/fiber/v2 (Ctx.Format) through version 2.52.12. The developer opts into content negotiation by calling AutoFormat(), but does not opt into raw HTML emission for a particular request; Fiber chooses that …

Description A Cross-Site Scripting (CWE-79) vulnerability in Go Fiber allows a remote attacker to inject arbitrary HTML/JavaScript by supplying Accept: text/html on any request whose handler passes attacker-influenced data to the AutoFormat() feature. This affects github.com/gofiber/fiber/v3 (DefaultRes.AutoFormat) through version 3.1.0 and github.com/gofiber/fiber/v2 (Ctx.Format) through version 2.52.12. The developer opts into content negotiation by calling AutoFormat(), but does not opt into raw HTML emission for a particular request; Fiber chooses that …

Fiber cache middleware's default key generator uses only c.Path() and does not include the query string. As a result, requests like /?id=1 and /?id=2 can map to the same cache key and share the same cached response. This can cause response mix-up (cache poisoning-like behavior) for endpoints where response content depends on query parameters.

The use of the fiber_flash cookie can force an unbounded allocation on any server. A crafted 10-character cookie value triggers an attempt to allocate up to 85GB of memory via unvalidated msgpack deserialization. No authentication is required. Every GoFiber v3 endpoint is affected regardless of whether the application uses flash messages.

Description A Path Traversal (CWE-22) vulnerability in Fiber allows a remote attacker to bypass the static middleware sanitizer and read arbitrary files on the server file system on Windows. This affects Fiber v3 through version 3.0.0. This has been patched in Fiber v3 version 3.1.0.

A denial of service vulnerability exists in Fiber v2 and v3 that allows remote attackers to crash the application by sending requests to routes with more than 30 parameters. The vulnerability results from missing validation during route registration combined with an unbounded array write during request matching.

A denial of service vulnerability exists in Fiber v2 and v3 that allows remote attackers to crash the application by sending requests to routes with more than 30 parameters. The vulnerability results from missing validation during route registration combined with an unbounded array write during request matching.

Fiber v2 contains an internal vendored copy of gofiber/utils, and its functions UUIDv4() and UUID() inherit the same critical weakness described in the upstream advisory. On Go versions prior to 1.24, the underlying crypto/rand implementation can return an error if secure randomness cannot be obtained. In such cases, these Fiber v2 UUID functions silently fall back to generating predictable values — the all-zero UUID 00000000-0000-0000-0000-000000000000. On Go 1.24+, the language …

When using Fiber's Ctx.BodyParser to parse form data containing a large numeric key that represents a slice index (e.g., test.18446744073704), the application crashes due to an out-of-bounds slice allocation in the underlying schema decoder. The root cause is that the decoder attempts to allocate a slice of length idx + 1 without validating whether the index is within a safe or reasonable range. If idx is excessively large, this leads …

When using the fiber.Ctx.BodyParser to parse into a struct with range values, a panic occurs when trying to parse a negative range index

A security vulnerability has been identified in the Fiber session middleware where a user can supply their own session_id value, leading to the creation of a session with that key.

A security vulnerability has been identified in the Fiber session middleware where a user can supply their own session_id value, leading to the creation of a session with that key.

A security vulnerability has been identified in the Fiber session middleware where a user can supply their own session_id value, leading to the creation of a session with that key.

Fiber is a web framework written in go. Prior to version 2.52.1, the CORS middleware allows for insecure configurations that could potentially expose the application to multiple CORS-related vulnerabilities. Specifically, it allows setting the Access-Control-Allow-Origin header to a wildcard (*) while also having the Access-Control-Allow-Credentials set to true, which goes against recommended security best practices. The impact of this misconfiguration is high as it can lead to unauthorized access to …

Fiber is an express inspired web framework written in Go. A Cross-Site Request Forgery (CSRF) vulnerability has been identified in the application, which allows an attacker to inject arbitrary values and forge malicious requests on behalf of a user. This vulnerability can allow an attacker to inject arbitrary values without any authentication, or perform various malicious actions on behalf of an authenticated user, potentially compromising the security and integrity of …

Fiber is an express inspired web framework written in Go. A Cross-Site Request Forgery (CSRF) vulnerability has been identified in the application, which allows an attacker to obtain tokens and forge malicious requests on behalf of a user. This can lead to unauthorized actions being taken on the user's behalf, potentially compromising the security and integrity of the application. The vulnerability is caused by improper validation and enforcement of CSRF …

Fiber is an Express inspired web framework built in the go language. Versions of gofiber prior to 2.49.2 does not properly restrict access to localhost. This issue impacts users of our project who rely on the ctx.IsFromLocal method to restrict access to localhost requests. If exploited, it could allow unauthorized access to resources intended only for localhost. Setting X-Forwarded-For: 127.0.0.1 in a request from a foreign host, will result in …

Fiber is an Express inspired web framework built in the go language. Versions of gofiber prior to 2.49.2 does not properly restrict access to localhost. This issue impacts users of our project who rely on the ctx.IsFromLocal method to restrict access to localhost requests. If exploited, it could allow unauthorized access to resources intended only for localhost. Setting X-Forwarded-For: 127.0.0.1 in a request from a foreign host, will result in …

The Olivier Poitrey Go CORS handler through 1.3.0 actively converts a wildcard CORS policy into reflecting an arbitrary Origin header value, which is incompatible with the CORS security design, and could lead to CORS misconfiguration security problems.

In Fiber, the filename that is given in c.Attachment() is not escaped, and therefore vulnerable for a CRLF injection attack. An attacker could upload a custom filename and then give the link to the victim. With this filename, the attacker can change the name of the downloaded file, redirect to another site, change the authorization header, etc. A possible workaround is to serialize the input before passing it to ctx.Attachment().