CVE-2026-25542 Tekton Pipelines: VerificationPolicy regex pattern bypass via substring matching
Attackers can bypass trusted resource verification policies in Tekton Pipelines by using substring matching in regex patterns, altering which verification keys apply.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-25542?
CVE-2026-25542 is a medium-severity vulnerability in tektoncd pipeline, published on 21 Apr 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
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.
Weakness: CWE-185
Which versions are affected by CVE-2026-25542?
11 open source packages ship an affected version, including github.com/tektoncd/pipeline. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
github.com/tektoncd/pipeline Go | From 0.43.0 | 1.0.2, 1.3.4, 1.6.2, 1.9.3, 1.11.1 |
github.com/tektoncd/pipeline Go | From 0.43.0 | 1.0.2 |
github.com/tektoncd/pipeline Go | From 0.43.0 | 1.0.2 |
github.com/tektoncd/pipeline Go | From 1.10.0 | 1.11.1 |
github.com/tektoncd/pipeline Go | From 1.10.0 | 1.11.1 |
github.com/tektoncd/pipeline Go | From 1.2.0 | 1.3.4 |
5 more packages
github.com/tektoncd/pipeline Go | From 1.2.0 | 1.3.4 |
github.com/tektoncd/pipeline Go | From 1.4.0 | 1.6.2 |
github.com/tektoncd/pipeline Go | From 1.4.0 | 1.6.2 |
github.com/tektoncd/pipeline Go | From 1.7.0 | 1.9.3 |
github.com/tektoncd/pipeline Go | From 1.7.0 | 1.9.3 |
Products include Linuxfoundation Tekton Pipelines.
How do I fix CVE-2026-25542?
Upgrade github.com/tektoncd/pipeline to a fixed version for your release line: 1.0.2, 1.3.4, 1.6.2 or 1.9.3.
Is CVE-2026-25542 being exploited?
There is no known exploitation of CVE-2026-25542 in the wild and no public exploit code.
Other vulnerabilities in tektoncd pipeline
- CVE-2026-33211 Tekton Pipelines git resolver has path traversal that allows reading arbitrary files from the resolver pod
- CVE-2026-40161 Tekton Pipelines: Git resolver API mode leaks system-configured API token to user-controlled serverURL
- CVE-2026-40938 Tekton Pipelines: Git Resolver Unsanitized Revision Parameter Enables git Argument Injection Leading to RCE
- CVE-2026-40924 Tekton Pipelines: HTTP Resolver Unbounded Response Body Read Enables Denial of Service via Memory Exhaustion
- CVE-2026-33022 Tekton Pipelines: Controller can panic when setting long resolver names in TaskRun/PipelineRun
Sources
Also known as CLEANSTART-2026-VQ84921, GHSA-rmx9-2pp3-xhcr, GO-2026-5630.