CVE-2026-29186

Description

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.

PUBLISHED Reserved 2026-03-04 | Published 2026-03-07 | Updated 2026-03-07 | Assigner GitHub_M

Problem types

CWE-434: Unrestricted Upload of File with Dangerous Type

CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')

Product status

References

github.com/...kstage/security/advisories/GHSA-928r-fm4v-mvrw

cve.org (CVE-2026-29186)

nvd.nist.gov (CVE-2026-29186)

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