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
- Run
go list -m github.com/external-secrets/external-secretsin your project to see the installed version, including copies pulled in by other packages. - Or paste your lockfile into the checker: it lists every package with a known vulnerability, this one included.
How to fix
Copies a prompt for Claude Code, Cursor or Codex: it checks your lockfiles for this and upgrades it.
- Upgrade
github.com/external-secrets/external-secretsto 1.3.2 or later, commit the lockfile and redeploy. - 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)
Check your whole app
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References
- github.com/external-secrets/external-secrets/security/advisories/GHSA-q7hv-xx6h-q2x8
- github.com/external-secrets/external-secrets/commit/25aa09275861e3ed6fc5d2a1a60b9ac3df4a93ba
- github.com/external-secrets/external-secrets/pull/5901
- github.com/external-secrets/external-secrets/releases/tag/v1.3.2
- github.com/external-secrets/external-secrets
Merged from OSV. Last updated 24 Oct 2026. All vulnerabilities · RSS · JSON