Cyber Resilience

CVE-2026-25542

Linuxfoundation Tekton Pipelines 0.43.0 – 1.11.0

Public PoC
Published
21 April 2026
Modified
22 May 2026
Patch / advisory
CVSS Score v3.1 6.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
EPSS Score 0.0026 18th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2026-25542 is a medium-severity Incorrect Regular Expression (CWE-185) vulnerability in Linuxfoundation Tekton Pipelines. Its CVSS base score is 6.5 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Compromise Software Supply Chain (T1195.002); ranked at the 18th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to AC-3 (Access Enforcement) and SI-10 (Information Input Validation) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

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,…

more

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.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1195.002 Compromise Software Supply Chain Initial Access
Adversaries may manipulate application software prior to receipt by a final consumer for the purpose of data or system compromise.
Why these techniques?

Bypass of trusted resource verification policies via regex substring matching directly enables compromise of the software supply chain by allowing untrusted/malicious pipeline resources to be accepted.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2026-40938Same product: Linuxfoundation Tekton Pipelines
CVE-2026-33022Same product: Linuxfoundation Tekton Pipelines
CVE-2026-33211Same product: Linuxfoundation Tekton Pipelines
CVE-2026-40923Same product: Linuxfoundation Tekton Pipelines
CVE-2023-37264Same product: Linuxfoundation Tekton Pipelines
CVE-2026-40161Same product: Linuxfoundation Tekton Pipelines
CVE-2026-40924Same product: Linuxfoundation Tekton Pipelines
CVE-2026-50195Same vendor: Linuxfoundation
CVE-2025-59354Same vendor: Linuxfoundation
CVE-2023-30840Same vendor: Linuxfoundation

Affected Assets

linuxfoundation
tekton pipelines
0.43.0 — 1.11.0

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • SI-10 Information Input Validation
  • AC-3 Access Enforcement
  • AC-4 Information Flow Enforcement
Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly requires validation of untrusted input (refSource.URI) against policy patterns so that regexp substring matching bypasses are rejected.

prevent

Enforces the intended verification-mode and key decisions that the flawed policy match is currently allowing an attacker to subvert.

prevent

Implements information-flow rules that decide which resources may be processed; the broken regexp match undermines those flow decisions.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly require correct regex design, testing, and review to avoid improper matching.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

detects

Security testing in development can detect regex-related flaws before release.

prevents

Secure development lifecycle includes validation of input-handling constructs such as regex.

prevents

Application security requirements can mandate correct regex design and testing.

prevents

Secure coding standards directly address proper construction and review of regular expressions.

References