{"id":"CVE-2026-26287","aliases":["GHSA-q7hv-xx6h-q2x8","GO-2026-6667"],"url":"https://o3.security/vulnerability/CVE-2026-26287","summary":"External Secrets Operator: label enforcement bypass in webhook generator enables secret exfiltration","details":"## Summary\nA 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`.\n\n## Impact\nA 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.\n\n## Mitigations\nUntil you upgrade, you can reduce risk by:\n- disabling webhook generators if not needed (or denying `generators.external-secrets.io/v1alpha1` `Webhook` via an admission policy);\n- restricting RBAC: limit who can create generators of kind `Webhook`;\n- enforcing an admission policy (OPA Gatekeeper / Kyverno) requiring referenced secrets to be labeled `external-secrets.io/type=webhook`;\n- restricting egress from external-secrets controller pods to an allowlist (kubernetes `NetworkPolicy` / service mesh egress policy).\n\n## References\n- PR #5901 (fix: webhook initialization order)","published":"2026-10-06T15:31:56.088Z","modified":"2026-10-21T02:56:32.468649089Z","cvss":{"score":7.1,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"Go","name":"github.com/external-secrets/external-secrets","fixedVersion":"1.3.2"}],"fix":{"url":"https://github.com/external-secrets/external-secrets/commit/25aa09275861e3ed6fc5d2a1a60b9ac3df4a93ba","label":"external-secrets/external-secrets@25aa092"},"references":[{"type":"WEB","url":"https://github.com/external-secrets/external-secrets/releases/tag/v1.3.2"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/26xxx/CVE-2026-26287.json"},{"type":"ADVISORY","url":"https://github.com/external-secrets/external-secrets/security/advisories/GHSA-q7hv-xx6h-q2x8"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-26287"},{"type":"FIX","url":"https://github.com/external-secrets/external-secrets/commit/25aa09275861e3ed6fc5d2a1a60b9ac3df4a93ba"},{"type":"FIX","url":"https://github.com/external-secrets/external-secrets/pull/5901"},{"type":"PACKAGE","url":"https://github.com/external-secrets/external-secrets"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-10-21T02:56:32.468649089Z"}}