CVE-2026-106509 HIGH

CVE-2026-106509: Backstage: Improper validation of MkDocs theme configuration in TechDocs

Vendor Backstage
Product backstage
Weakness CWE-94 · Code injection
Published October 6, 2026
Last update October 6, 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 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 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.

Key dates

02Disclosure timeline

October 6, 2026 CVE published

Related vulnerabilities

04Related CVE