CVE-2026-106558: @backstage Plugin-Techdocs-Node

High severity, CVSS 8.8. EPSS: 0.5% chance of exploitation in the next 30 days.

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.

Affected products

• @backstage Plugin-Techdocs-Node: before 1.14.8 (fixed in 1.14.8); from 1.15.0, before 1.15.6 (fixed in 1.15.6); from 2.0.0, before 2.0.1 (fixed in 2.0.1)
• Backstage Backstage: before 1.50.7 (fixed in 1.50.7); from 1.51.0-next.0, before 1.54.9 (fixed in 1.54.9); from 1.55.0-next.0, before 1.55.2 (fixed in 1.55.2)

Published 2026-10-07. Last modified 2026-10-10.