# 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. - **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N`) - **Exploited in the wild:** Not known - **Login needed:** Any signed-in user - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 21 Apr 2026 - **Updated:** 22 May 2026 - **Also known as:** CLEANSTART-2026-VQ84921, GHSA-rmx9-2pp3-xhcr, GO-2026-5630 ## 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 (Incorrect Regular Expression) ## 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 | Ecosystem | 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 | | `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: 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](https://insights.sbomify.com/CVE-2026-33211/): Tekton Pipelines git resolver has path traversal that allows reading arbitrary files from the resolver pod (critical 9.6) - [CVE-2026-40161](https://insights.sbomify.com/CVE-2026-40161/): Tekton Pipelines: Git resolver API mode leaks system-configured API token to user-controlled serverURL (high 7.7) - [CVE-2026-40938](https://insights.sbomify.com/CVE-2026-40938/): Tekton Pipelines: Git Resolver Unsanitized Revision Parameter Enables git Argument Injection Leading to RCE (high 7.5) - [CVE-2026-40924](https://insights.sbomify.com/CVE-2026-40924/): Tekton Pipelines: HTTP Resolver Unbounded Response Body Read Enables Denial of Service via Memory Exhaustion (medium 6.5) - [CVE-2026-33022](https://insights.sbomify.com/CVE-2026-33022/): Tekton Pipelines: Controller can panic when setting long resolver names in TaskRun/PipelineRun (medium 6.5) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2026-25542 and fix it if it is affected. What it is: 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. Exploitation: There is no known exploitation of CVE-2026-25542 in the wild and no public exploit code. Affected packages and fixed versions: - github.com/tektoncd/pipeline (Go): affected from 0.43.0; fixed in 1.0.2, 1.3.4, 1.6.2, 1.9.3, 1.11.1 - github.com/tektoncd/pipeline (Go): affected from 0.43.0; fixed in 1.0.2 - github.com/tektoncd/pipeline (Go): affected from 0.43.0; fixed in 1.0.2 - github.com/tektoncd/pipeline (Go): affected from 1.10.0; fixed in 1.11.1 - github.com/tektoncd/pipeline (Go): affected from 1.10.0; fixed in 1.11.1 - github.com/tektoncd/pipeline (Go): affected from 1.2.0; fixed in 1.3.4 - github.com/tektoncd/pipeline (Go): affected from 1.2.0; fixed in 1.3.4 - github.com/tektoncd/pipeline (Go): affected from 1.4.0; fixed in 1.6.2 - github.com/tektoncd/pipeline (Go): affected from 1.4.0; fixed in 1.6.2 - github.com/tektoncd/pipeline (Go): affected from 1.7.0; fixed in 1.9.3 - github.com/tektoncd/pipeline (Go): affected from 1.7.0; fixed in 1.9.3 Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2026-25542/ (Markdown: https://insights.sbomify.com/CVE-2026-25542/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2026-25542 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-25542 - OSV: https://osv.dev/vulnerability/CVE-2026-25542 --- From sbomify Insights: https://insights.sbomify.com/CVE-2026-25542/ Summaries are generated and may contain mistakes; the official description above is the record.