CVE-2026-88064

Backstage: Improper input validation in TechDocs MkDocs configuration

Published Sep 16, 2026 CVSS 3.1 · 8.8 High EPSS 1.2% KEV · Not listed
Description
Backstage is an open framework for building developer portals. Prior to 1.14.6 and from 1.15.0 until 1.15.4, the @backstage/plugin-techdocs-node package insufficiently validates mkdocs.yml supplied by an authenticated user who can register or modify a TechDocs source. Unsafe Python YAML tags, markdown_extensions names and configuration, theme options, and extra_templates values can reach the documentation generator and cause unintended code execution. The resulting impact is limited to the files, credentials, network access, and other resources available to the TechDocs backend or build container. This issue is fixed in versions 1.14.6 and 1.15.4.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Linuxfoundation
Linuxfoundation backstage
Linuxfoundation backstage Plugin-techdocs-node
CPEs cpe:2.3:a:linuxfoundation:backstage:*:*:*:*:*:*:*:*
cpe:2.3:a:linuxfoundation:backstage_plugin-techdocs-node:*:*:*:*:*:*:*:*
Vendors & Products Linuxfoundation
Linuxfoundation backstage
Linuxfoundation backstage Plugin-techdocs-node
Type Values Removed Values Added
First Time appeared Backstage
Backstage backstage
Vendors & Products Backstage
Backstage backstage
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description Backstage is an open framework for building developer portals. Prior to 1.14.6 and from 1.15.0 until 1.15.4, the @backstage/plugin-techdocs-node package insufficiently validates mkdocs.yml supplied by an authenticated user who can register or modify a TechDocs source. Unsafe Python YAML tags, markdown_extensions names and configuration, theme options, and extra_templates values can reach the documentation generator and cause unintended code execution. The resulting impact is limited to the files, credentials, network access, and other resources available to the TechDocs backend or build container. This issue is fixed in versions 1.14.6 and 1.15.4.
Title Backstage: Improper input validation in TechDocs MkDocs configuration
Weaknesses CWE-1336
CWE-20
References
Metrics cvssV3_1

{'score': 8.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Sep 16, 2026, 3:46 PM
Reserved
Sep 9, 2026, 9:22 PM
Status
Analyzed
Published
Sep 16, 2026, 3:18 PM
Modified
Oct 14, 2026, 6:02 PM