CVE-2026-29186

Summary

Backstage is an open framework for building developer portals. Prior to version 1.14.3, this is a configuration bypass vulnerability that enables arbitrary code execution. The @backstage/plugin-techdocs-node package uses an allowlist to filter dangerous MkDocs configuration keys during the documentation build process. A gap in this allowlist allows attackers to craft an mkdocs.yml that causes arbitrary Python code execution, completely bypassing TechDocs' security controls. This issue has been patched in version 1.14.3.

Affected Software

VendorProductVersion RangeStatus
backstagebackstage< 1.14.3affected

Weaknesses

  • CWE-434: CWE-434: Unrestricted Upload of File with Dangerous Type
  • CWE-74: CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: total

backstage/plugin-techdocs-node: TechDocs Mkdocs configuration key enables arbitrary code execution

Additional References

References