Advisories for Golang/Github.com/External-Secrets/External-Secrets package

2026

External Secrets Operator has Namespace Isolation Bypass in CAProvider ConfigMap Resolution for SecretStore

Namespaced SecretStore resources that used CAProvider with type ConfigMap could resolve CA material from another namespace when caProvider.namespace was set. This bypassed the namespace boundary enforced for SecretStore-backed references in providers that rely on the shared runtime CA resolver. The accessible data is used as CA validation material, hence it is not directly exposed. Impact: Direct data exfiltration risk: low Existence disclosure: an attacker can infer whether a target ConfigMap/key …

External Secrets Operator has DNS-based secret exfiltration via getHostByName in External Secrets v2 template engine

The v2 template engine in runtime/template/v2/template.go imports Sprig’s TxtFuncMap() and removes env and expandenv, but leaves getHostByName available to user-controlled templates. Because ESO executes templates inside the controller process, an attacker who can create or update templated ExternalSecret resources can trigger controller-side DNS lookups using secret-derived values, creating a DNS exfiltration primitive.

External Secrets Operator insecurely retrieves secrets through the getSecretKey templating function

The getSecretKey template function, while introduced for senhasegura Devops Secrets Management (DSM) provider, has the ability to fetch secrets cross-namespaces with the roleBinding of the external-secrets controller, bypassing our security mechanisms. This function was completely removed, as everything done with that templating function can be done in a different way while respecting our safeguards (for example, using sourceRef like explained here: https://github.com/external-secrets/external-secrets/issues/5690#issuecomment-3630977865)

2025

External Secrets Operator's Missing Namespace Restriction Allows Unauthorized Secret Access

A vulnerability was discovered in the External Secrets Operator where the List() calls for Kubernetes Secret and SecretStore resources performed by the PushSecret controller did not apply a namespace selector. This flaw allowed an attacker to use label selectors to list and read secrets/secret-stores across the cluster, bypassing intended namespace restrictions.

2024