high Patched

External Secrets Operator: label enforcement bypass in webhook generator enables secret exfiltration

CVE-2026-26287 · GHSA-q7hv-xx6h-q2x8 · GO-2026-6667 · published 6 Oct 2026

How serious is it

  • Severity: high.
  • No exploit prediction (EPSS) score yet.
  • Not on the CISA list of exploited vulnerabilities.
  • No public exploit in Exploit-DB.

Is your app affected by CVE-2026-26287?

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Who is affected

  • github.com/external-secrets/external-secrets (Go) >= 0.10.0, < 1.3.2

How to check

  1. Run go list -m github.com/external-secrets/external-secrets in your project to see the installed version, including copies pulled in by other packages.
  2. Or paste your lockfile into the checker: it lists every package with a known vulnerability, this one included.

How to fix

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  1. Upgrade github.com/external-secrets/external-secrets to 1.3.2 or later, commit the lockfile and redeploy.
  2. If a vulnerable version was live, check your logs and rotate the secrets that server could read.

The advisory

## Summary A bug in the `webhook` generator initialization order incorrectly cleared the label-enforcement flag (`EnforceLabels`) after it was set, resulting in the provider-side check for `external-secrets.io/type=webhook` being skipped (and the operation to succeed while it should have failed with `secret does not contain needed label 'external-secrets.io/type: webhook'. Update secret label to use it with webhook`. ## Impact A user with the permission to create webhook generator can set the webhook generator to a victim' secret (which was not previously labelled for webhook's use), and exfiltrate it to a malicious URL. ## Mitigations Until you upgrade, you can reduce risk by: - disabling webhook generators if not needed (or denying `generators.external-secrets.io/v1alpha1` `Webhook` via an admission policy); - restricting RBAC: limit who can create generators of kind `Webhook`; - enforcing an admission policy (OPA Gatekeeper / Kyverno) requiring referenced secrets to be labeled `external-secrets.io/type=webhook`; - restricting egress from external-secrets controller pods to an allowlist (kubernetes `NetworkPolicy` / service mesh egress policy). ## References - PR #5901 (fix: webhook initialization order)

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References

Merged from OSV. Last updated 24 Oct 2026. All vulnerabilities · RSS · JSON