CVE-2026-106509

Backstage: Improper validation of MkDocs theme configuration in TechDocs

State
Published
Severity
7.7 High
Published
Oct 6, 2026
Updated
Oct 7, 2026
Reserved
Oct 6, 2026

Read the record on cve.org

Description

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.

Scores

CVSSScoreVectorSource
3.17.7 HighCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:LGitHub_M

Weaknesses

  • CWE-94 Improper Control of Generation of Code ('Code Injection')
  • CWE-1336 Improper Neutralization of Special Elements Used in a Template Engine

Affected Products

ProductVersions
backstagebackstage
  • < 1.50.5Affected
  • >= 1.51.0-next.0, < 1.54.6Affected
plugin-techdocs-node@backstage
  • < 1.14.6Affected
  • >= 1.15.0, < 1.15.4Affected

References

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