CVE-2026-29186 HIGH

CVE-2026-29186: @backstage/plugin-techdocs-node: TechDocs Mkdocs Configuration Key Enables Arbitrary Code Execution

Vendor Backstage
Product backstage
Weakness CWE-434 · Unrestricted file upload
Published March 7, 2026
Last update June 30, 2026

CVSS base score

7.7/10
Attack vector Network
Attack complexity High
Privileges required Low
User interaction None
Confidentiality High
Integrity Low

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:L

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

March 7, 2026 CVE published
June 30, 2026 Record updated