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Fencer Vulns
medium 5.4

CVE-2026-40923 json

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

published 2026-04-21 6 mo ago modified 2026-10-26 13 d ago also GHSA-rx35-6rhx-7858 , GO-2026-5643 , EUVD-2026-24481

cvss
5.4
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 12%
public exploits
0
none known

Summary

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.

Patch / fix

  • go github.com/tektoncd/pipeline 1.0.2, 1.3.4, 1.6.2, 1.9.3, 1.11.1
  • linuxfoundation tekton_pipelines 1.11.1
  • govulncheck-vulndb openSUSE Leap 16.0 0.0.20260723T184607-160000.1.1

opensuse advisories openSUSE-SU-2026:21483-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-40923 updated cvss 5.4

github.com/tektoncd/pipeline: Tekton Pipelines: Unauthorized access and information disclosure via path validation bypass

  • Red Hat Builds for Red Hat OpenShift openshift-builds/openshift-builds-waiters-rhel9, openshift-builds/openshift-builds-webhook-rhel9, openshift-builds/openshift-builds-rhel9-operator, openshift-builds/openshift-builds-controller-rhel9, openshift-builds/openshift-builds-git-cloner-rhel9, openshift-builds/openshift-builds-image-bundler-rhel9, +1 more Red Hat OpenShift Pipelines openshift-pipelines/pipelines-opc-rhel9, openshift-pipelines/pipelines-cli-tkn-rhel8, openshift-pipelines/pipelines-cli-tkn-rhel9, openshift-pipelines/pipelines-hub-api-rhel8, openshift-pipelines/pipelines-hub-api-rhel9, openshift-pipelines/pipelines-git-init-rhel8, +32 more Red Hat OpenShift Serverless openshift-serverless-1/kn-client-kn-rhel9, openshift-serverless-1/kn-plugin-func-func-util-rhel9
    affected: no fix available “Fix deferred”
  • Red Hat OpenShift AI (RHOAI) rhoai/odh-ml-pipelines-driver-rhel8, rhoai/odh-ml-pipelines-launcher-rhel8, rhoai/odh-ml-pipelines-api-server-v2-rhel8, rhoai/odh-ml-pipelines-persistenceagent-v2-rhel8, rhoai/odh-ml-pipelines-scheduledworkflow-v2-rhel8 Red Hat OpenShift Virtualization 4 container-native-virtualization/kubevirt-ssp-operator-rhel9, container-native-virtualization/kubevirt-template-validator-rhel9, container-native-virtualization/kubevirt-tekton-tasks-create-datavolume-rhel9, container-native-virtualization/kubevirt-tekton-tasks-disk-virt-customize-rhel9 Red Hat Trusted Artifact Signer rhtas/ec-rhel9
    affected: no fix planned “Out of support scope”
  • Red Hat OpenShift Lightspeed openshift-lightspeed/openshift-mcp-server-rhel9 Red Hat OpenShift Pipelines openshift-pipelines/pipelines-nop-rhel8, openshift-pipelines/pipelines-nop-rhel9, openshift-pipelines/pipelines-events-rhel8, openshift-pipelines/pipelines-events-rhel9, openshift-pipelines/pipelines-webhook-rhel8, openshift-pipelines/pipelines-webhook-rhel9, +10 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
6 mo ago

Exploit prediction

0.22% chance of exploitation in the next 30 days, higher than 12% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 5.4 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
GitHub 3.1 5.4 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

Affected packages

ecosystem package affected fixed in
go github.com/tektoncd/pipeline
>=1.10.0, <1.11.1
>=1.7.0, <1.9.3
>=1.4.0, <1.6.2
>=1.2.0, <1.3.4
>=1.0.0, <1.0.2
>=1.1.0, <1.3.4
1.11.1
1.9.3
1.6.2
1.3.4
1.0.2

Affected products

  • tektoncd pipeline

Classification

Weakness
  • CWE-22 Improper Limitation of a Pathname to a Restricted Directory

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.