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.
CVE-2026-25542
MEDIUMNVD 6.56.5—
EchelonGraph scoreMEDIUM confidence
This medium-severity CVE scores 6.5 under NVD CVSS v3. EPSS exploit probability: 0.0%, top 88% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
Triggered by: NVD CVSS baseline
Sources: epss, nvd
6.5
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
- Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 6.5Exploit: NoneExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 6.5
- EG Score
- 6.5(medium)
- EPSS
- 17.8%
- KEV
- Not listed
Published
April 21, 2026
Last Modified
May 22, 2026
Advisory Details (2)
Auto-updated May 1, 2026🔬 Proof of concept available. Patch available. Sources: github.
github Patch Available🟡 PoC Available
VerificationPolicy regex pattern bypass via substring matching · Advisory · tektoncd/pipeline · GitHub
https://github.com/tektoncd/pipeline/security/advisories/GHSA-rmx9-2pp3-xhcrgeneric
fix: strip resolver prefixes and use non-capturing group for pattern … · tektoncd/pipeline@b890560 · GitHub
https://github.com/tektoncd/pipeline/commit/b8905600322aa86327baae0a7c04d6cf1207362aVendor Advisories for CVE-2026-25542(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Affected Packages
(1 across 1 ecosystem)
Go(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| github.com/tektoncd/pipeline | — | 1.11.1 | — |
Frequently asked(5)
What is CVE-2026-25542?
CVE-2026-25542 is a medium vulnerability published on April 21, 2026. 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…
When was CVE-2026-25542 disclosed?
CVE-2026-25542 was first published in the National Vulnerability Database on April 21, 2026, with the most recent update on May 22, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-25542 actively exploited?
CVE-2026-25542 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 17.8% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-25542?
CVE-2026-25542 has a CVSS v3 base score of 6.5 (NVD).
How do I remediate CVE-2026-25542?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-25542, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-25542
Is Your Infrastructure Affected by CVE-2026-25542?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.