{"id":"CVE-2026-40923","aliases":["GHSA-rx35-6rhx-7858","GO-2026-5643"],"url":"https://o3.security/vulnerability/CVE-2026-40923","summary":"Tekton Pipelines: VolumeMount path restriction bypass via missing filepath.Clean in /tekton/ check","details":"Tekton Pipelines project provides k8s-style resources for declaring CI/CD-style pipelines. Starting in version 1.0.0 and prior to versions 1.0.2, 1.3.4, 1.6.2, 1.9.3, and 1.11.1, a validation bypass in the VolumeMount path restriction allows mounting volumes under restricted /tekton/ internal paths by using .. path traversal components. The restriction check uses strings.HasPrefix without filepath.Clean, so a path like /tekton/home/../results passes validation but resolves to /tekton/results at runtime. Versions 1.0.2, 1.3.4, 1.6.2, 1.9.3, and 1.11.1 fix the issue.","published":"2026-04-21T20:50:53.742Z","modified":"2026-08-12T03:51:24.789518233Z","cvss":{"score":5.4,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N"},"epss":{"score":0.0022,"percentile":0.12669,"asOf":"2026-08-12"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"github.com/tektoncd/pipeline","fixedVersion":"1.11.1"},{"ecosystem":"Go","name":"github.com/tektoncd/pipeline","fixedVersion":"1.9.3"},{"ecosystem":"Go","name":"github.com/tektoncd/pipeline","fixedVersion":"1.6.2"},{"ecosystem":"Go","name":"github.com/tektoncd/pipeline","fixedVersion":"1.3.4"},{"ecosystem":"Go","name":"github.com/tektoncd/pipeline","fixedVersion":"1.0.2"}],"fix":null,"references":[{"type":"WEB","url":"https://github.com/tektoncd/pipeline/releases/tag/v1.11.1"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/40xxx/CVE-2026-40923.json"},{"type":"ADVISORY","url":"https://github.com/tektoncd/pipeline/security/advisories/GHSA-rx35-6rhx-7858"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-40923"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:24.789518233Z"}}