Tekton Pipelines: VolumeMount path restriction bypass via missing filepath.Clean in /tekton/ check

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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.

Source published

21 Apr 2026 20:50:53 UTC

Source modified

22 May 2026 15:41:51 UTC

Observed here

23 Oct 2026 15:48:27 UTC

Source terms

CVE Program Terms of Use

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: cve-program · CVE Program Terms of Use. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 3.1 · 5.4 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

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.

Source published

Apr 21, 2026, 8:50:53 PM (timezone not stated)

Source modified

May 22, 2026, 3:41:51 PM (timezone not stated)

Observed here

1 Nov 2026 07:05:15 UTC

Source terms

ENISA EUVD · source terms and attribution apply

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: euvd · ENISA EUVD · source terms and attribution apply. Source text is retained; field grouping and change labels are provided by ChangeIntel.

EUVD CVSS 3.1 · 5.4 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

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.

Source published

21 Apr 2026 21:16:45 UTC

Source modified

26 Oct 2026 22:10:00 UTC

Observed here

27 Oct 2026 10:10:07 UTC

Source terms

NIST NVD usage terms; underlying source attribution retained

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: nvd · NIST NVD usage terms; underlying source attribution retained. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 3.1 · [email protected] · Secondary · 5.4 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

### Summary 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. ### Details Tekton Pipelines restricts VolumeMount paths under `/tekton/` (except `/tekton/home`) to prevent users from interfering with internal execution state. The validation at `pkg/apis/pipeline/v1/container_validation.go` checks mount paths using `strings.HasPrefix` without normalizing the path first: ```go if strings.HasPrefix(vm.MountPath, "/tekton/") && !strings.HasPrefix(vm.MountPath, "/tekton/home") { // reject } ``` Because `/tekton/home` is an allowed prefix, a path like `/tekton/home/../results` passes both checks. At runtime, the container runtime resolves `..` and the actual mount point becomes `/tekton/results`. The same pattern exists in `pkg/apis/pipeline/v1beta1/task_validation.go`. ### Impact An authenticated user with Task or TaskRun creation permissions can mount volumes over internal Tekton paths, potentially: - Writing fake task results that downstream pipelines trust - Reading or modifying step scripts before execution - Interfering with entrypoint coordination state ### Patches _(to be filled: fixed in versions X.Y.Z)_ ### Workarounds - Use admission controllers (OPA/Gatekeeper, Kyverno) to validate that VolumeMount paths do not contain `..` components. - In multi-tenant setups, restrict who can create Task and TaskRun resources via RBAC. ### Affected Versions All versions through **v1.10.0** (both `v1` and `v1beta1` APIs). ### Acknowledgments This vulnerability was reported by @kodareef5.

Source published

21 Apr 2026 20:26:41 UTC

Source modified

10 Sep 2026 03:51:03 UTC

Observed here

24 Oct 2026 13:19:41 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V3 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

Publisher rating · MODERATE

Tekton Pipelines VolumeMount path restriction bypass via missing filepath.Clean in github.com/tektoncd/pipeline

Source published

25 Jun 2026 22:34:38 UTC

Source modified

23 Jul 2026 19:15:17 UTC

Observed here

24 Oct 2026 13:19:41 UTC

Source terms

OSV · upstream source license applies

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · OSV · upstream source license applies. Source text is retained; field grouping and change labels are provided by ChangeIntel.