Tekton Pipelines: VerificationPolicy regex pattern bypass via substring matching

Summary

Tekton Pipelines project provides k8s-style resources for declaring CI/CD-style pipelines. Starting in version 0.43.0 and prior to versions 1.0.2, 1.3.4, 1.6.2, 1.9.3, and 1.11.1, trusted resources verification policies match a resource source string (refSource.URI) against spec.resources[].pattern using regexp.MatchString. In Go, regexp.MatchString reports a match if the pattern matches anywhere in the string, so common unanchored patterns (including examples in tekton documentation) can be bypassed by attacker-controlled source strings that contain the trusted pattern as a substring. This can cause an unintended policy match and change which verification mode/keys apply. Versions 1.0.2, 1.3.4, 1.6.2, 1.9.3, and 1.11.1 fix the issue.

Timeline

1. Apr 21, 2026, 4:05 PM UTCCVE published
2. Apr 21, 2026, 4:48 PM UTCCISA SSVC assessment

   Exploitation: none · Automatable: no · Technical impact: partial

3. May 22, 2026, 4:06 PM UTCRecord last updated

Affected versions

• tektoncd pipeline

  From 0.43.0 · fixed in 1.0.2; From 1.2.0 · fixed in 1.3.4; From 1.4.0 · fixed in 1.6.2; From 1.7.0 · fixed in 1.9.3; From 1.10.0 · fixed in 1.11.1

• github.com/tektoncd/pipelineGo

  From 0.43.0 · fixed in 1.0.2

• github.com/tektoncd/pipelineGo

  From 1.2.0 · fixed in 1.3.4

• github.com/tektoncd/pipelineGo

  From 1.4.0 · fixed in 1.6.2

• github.com/tektoncd/pipelineGo

  From 1.7.0 · fixed in 1.9.3

• github.com/tektoncd/pipelineGo

  From 1.10.0 · fixed in 1.11.1

• github.com/tektoncd/pipelineGo

  From 0.43.0 · fixed in 1.0.2; From 1.1.0 · fixed in 1.3.4; From 1.4.0 · fixed in 1.6.2; From 1.7.0 · fixed in 1.9.3; From 1.10.0 · fixed in 1.11.1

References 2