Raw vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:NSummary
CVE-2026-40923 is a medium-severity Path Traversal (CWE-22) vulnerability in Linuxfoundation Tekton Pipelines. Its CVSS base score is 5.4 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 13th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
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.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-24481
Vulnerability Data
Tekton Pipelines project provides k8s-style resources for declaring CI/CD-style pipelines. Starting in version 1.0.0 and prior to versions 1.0.2, 1.3.4, 1.6.2, 1.9.3, and 1.11.1, a validation bypass in the VolumeMount path restriction allows mounting volumes under restricted /tekton/ internal paths…
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by using .. path traversal components. The restriction check uses strings.HasPrefix without filepath.Clean, so a path like /tekton/home/../results passes validation but resolves to /tekton/results at runtime. 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
Why these techniques?
Path traversal bypass on VolumeMount restrictions enables mounting internal /tekton paths, directly facilitating privilege escalation within the Kubernetes CI/CD context.
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V5.3.2
Mitigating Controls (NIST 800-53 r5) AI
Requires validation of all input paths (including VolumeMount targets) to reject path traversal sequences such as .. before any prefix or resolution checks occur.
Enforces the intended restriction that prevents volume mounts under internal /tekton/ paths, directly blocking the bypass that allows unauthorized access to restricted directories.
Verifies integrity of pipeline controller binaries and configuration to ensure the filepath.Clean logic and path checks cannot be altered or bypassed at runtime.
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.
Patching/maintenance can remediate known path-traversal flaws in deployed software (partial prevention of exploitability) but does nothing to stop the coding defect from being introduced in the first place.
PR.AA-05 defines and reviews access policies but does not address code-level pathname neutralization, so neither direction prevents CWE-22.
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.
Security testing in development catches path traversal via static/dynamic analysis.
Secure SDLC mandates input validation and path sanitization that directly prevent path traversal.
Application security requirements include rules for safe file handling and canonicalization.
Secure architecture principles require least-privilege file access and directory isolation.
Secure coding standards explicitly forbid unsafe path construction and mandate safe APIs.
Information access restriction limits which files an application may read or write.