CVE-2026-42876 External Secrets Operator: Privilege escalation with secret overwriting
Users with ExternalSecret creation permissions can impersonate service accounts by forcing the operator to create long-lived token secrets.
- 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-2026-42876?
CVE-2026-42876 is a medium-severity 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 2.4.1, a user who only has permission to create ExternalSecret resources can cause the operator to create a Secret that Kubernetes will automatically populate with a long-lived token for the specified service account. This effectively allows the user to impersonate any service account in the namespace without needing direct create permissions on TokenRequest or Secrets of that type. This vulnerability is fixed in 2.4.1.
Weakness: CWE-285
Which versions are affected by CVE-2026-42876?
3 open source packages ship an affected version, including github.com/external-secrets/external-secrets/apis.
| Package | Affected | Fixed in |
|---|---|---|
github.com/external-secrets/external-secrets/apis Go | All versions | None |
github.com/external-secrets/external-secrets/apis Go | From 0.1.0 | 2.4.1 |
github.com/external-secrets/external-secrets/apis Go | From 0.1.0 | 2.4.1 |
How do I fix CVE-2026-42876?
Upgrade github.com/external-secrets/external-secrets/apis to 2.4.1 or later.
Is CVE-2026-42876 being exploited?
There is no known exploitation of CVE-2026-42876 in the wild and no public exploit code.
Sources
Also known as GHSA-fq7h-9x26-6j22, GO-2026-5377, MINI-55jf-w96x-jj7q, MINI-gcw7-q39r-j8x4.