CVE-2026-42875 External Secrets Operator: Namespace Isolation Bypass in CAProvider ConfigMap Resolution for SecretStore
Attackers can bypass namespace isolation to read CA material from other namespaces via misconfigured SecretStore resources in External Secrets Operator.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-42875?
CVE-2026-42875 is a medium-severity missing authorization vulnerability in external-secrets, published on 11 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
External Secrets Operator reads information from a third-party service and automatically injects the values as Kubernetes Secrets. Prior to 2.4.0, 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. This vulnerability is fixed in 2.4.0.
Which versions are affected by CVE-2026-42875?
3 open source packages ship an affected version, including github.com/external-secrets/external-secrets.
| Package | Affected | Fixed in |
|---|---|---|
github.com/external-secrets/external-secrets Go | All versions | None |
github.com/external-secrets/external-secrets Go | All versions | 2.4.0 |
github.com/external-secrets/external-secrets Go | All versions | 2.4.0 |
How do I fix CVE-2026-42875?
Upgrade github.com/external-secrets/external-secrets to 2.4.0 or later.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-42875 being exploited?
There is no known exploitation of CVE-2026-42875 in the wild and no public exploit code.
Sources
Also known as GHSA-wv26-88m5-6h59, GO-2026-5723, MINI-q32v-cmmw-6hmq, MINI-rvw6-j2q5-qc8f.