Raw vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:LCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2026-106509 is a high-severity Code Injection (CWE-94) vulnerability in Linuxfoundation Backstage. Its CVSS base score is 7.7 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Command and Scripting Interpreter (T1059); ranked at the 29th 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-6 (Least Privilege) and SA-11 (Developer Testing and Evaluation) — see the control section below for these in your framework.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-94074
Vulnerability Data
Backstage is an open framework for building developer portals. Prior to 1.14.6, the @backstage/plugin-techdocs-node package is affected by improper validation of mkdocs theme configuration in techdocs. When TechDocs is configured to build documentation locally or in a container, a user…
more
with write access to a registered repository can include configuration values in mkdocs.yml that cause arbitrary code execution during the documentation build process. This issue is fixed in versions 1.14.6 and 1.15.4.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
—
—
—
V1.3.7V1.3.10V1.3.1
Mitigating Controls (NIST 800-53 r5) AI
Least privilege limits the damage an injected code fragment can perform once executed.
Developer testing and evaluation finds code paths that accept and execute externally influenced strings.
Requiring documented secure development standards and tools enforces use of safe code-generation APIs and escaping.
Security engineering principles require use of safe templating APIs and proper escaping of external input.
Input validation directly stops untrusted data from being used to construct executable code without neutralization.
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's SDLC practices directly target injection flaws via secure coding and testing (mostly), yet as a single broad outcome it leaves many code-generation specifics unaddressed (partial).
PR.DS-10 protects runtime data confidentiality/integrity but has no bearing on neutralizing externally influenced input during code generation, so neither direction shows any preventive effect.
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.