CVE-2026-106558

Backstage: Improper validation of TechDocs MkDocs configuration

Published Oct 7, 2026 CVSS 3.1 · 8.8 High EPSS < 1% KEV · Not listed
Description
Backstage is an open framework for building developer portals. Prior to 1.14.8, 1.15.6, and 2.0.1, the @backstage/plugin-techdocs-node package improperly validated mapping-style markdown_extensions configuration. An authenticated attacker who can register or influence an SCM-backed documentation source may bypass TechDocs sanitization and cause Python objects to be imported and instantiated in the generator runtime, leading to arbitrary code execution. Earlier fixes in versions 1.14.6 and 1.15.4 did not fully address the supported mapping representation of markdown_extensions. Impact is greatest when documentation generation runs with backend credentials, filesystem access, or internal network access. This issue is fixed in versions 1.14.8, 1.15.6, and 2.0.1.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-qmw3-745m-w99g Backstage: Improper validation of TechDocs MkDocs configuration
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:1.51.0:-:*:*:*:*:*:*
cpe:2.3:a:linuxfoundation:backstage:1.51.0:next0:*:*:*:*:*:*
cpe:2.3:a:linuxfoundation:backstage:1.51.0:next1:*:*:*:*:*:*
cpe:2.3:a:linuxfoundation:backstage:1.51.0:next2:*:*:*:*:*:*
cpe:2.3:a:linuxfoundation:backstage:1.51.0:next3:*:*:*:*:*:*
cpe:2.3:a:linuxfoundation:backstage:1.55.0:-:*:*:*:*:*:*
cpe:2.3:a:linuxfoundation:backstage:1.55.0:next0:*:*:*:*:*:*
cpe:2.3:a:linuxfoundation:backstage:1.55.0:next1:*:*:*:*:*:*
cpe:2.3:a:linuxfoundation:backstage:1.55.0:next2:*:*:*:*:*:*
cpe:2.3:a:linuxfoundation:backstage_plugin-techdocs-node:*:*:*:*:*:*:*:*
Vendors & Products Linuxfoundation
Linuxfoundation backstage
Linuxfoundation backstage Plugin-techdocs-node
Type Values Removed Values Added
Metrics ssvc

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

Type Values Removed Values Added
First Time appeared Backstage
Backstage backstage
Backstage plugin-techdocs-node
Vendors & Products Backstage
Backstage backstage
Backstage plugin-techdocs-node
Type Values Removed Values Added
Description Backstage is an open framework for building developer portals. Prior to 1.14.8, 1.15.6, and 2.0.1, the @backstage/plugin-techdocs-node package improperly validated mapping-style markdown_extensions configuration. An authenticated attacker who can register or influence an SCM-backed documentation source may bypass TechDocs sanitization and cause Python objects to be imported and instantiated in the generator runtime, leading to arbitrary code execution. Earlier fixes in versions 1.14.6 and 1.15.4 did not fully address the supported mapping representation of markdown_extensions. Impact is greatest when documentation generation runs with backend credentials, filesystem access, or internal network access. This issue is fixed in versions 1.14.8, 1.15.6, and 2.0.1.
Title Backstage: Improper validation of TechDocs MkDocs configuration
Weaknesses CWE-502
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
Oct 10, 2026, 2:27 AM
Reserved
Oct 6, 2026, 8:31 PM
Status
Analyzed
Published
Oct 7, 2026, 3:17 PM
Modified
Oct 13, 2026, 2:25 PM