Answer in brief
CVE-2026-106558 records a High severity (CVSS 8.8) vulnerability in Backstage: Improper validation of TechDocs MkDocs configuration. The current sources do not mark it as known exploited. The current feed maps backstage/backstage (generic), @backstage/plugin-techdocs-node (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 8.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps backstage/backstage (generic), @backstage/plugin-techdocs-node (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| backstage/backstagegeneric | <1.50.7 || >=1.51.0-next.0 <1.54.9 || >=1.55.0-next.0 <1.55.2 | 1.50.7, 1.54.9, 1.55.2 |
| @backstage/plugin-techdocs-nodegeneric | <1.14.8 || >=1.15.0 <1.15.6 || >=2.0.0 <2.0.1 | 1.14.8, 1.15.6, 2.0.1 |
Published upstream
Oct 7, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 7, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Oct 7, 2026
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.
Quoted source text, attributed separately from HOL analysis.