High · CVSS 7.7CVE-2026-106556

Backstage: Configuration bypass in TechDocs mkdocs.yml sanitizationCVE-2026-106556

Answer in brief

CVE-2026-106556 records a High severity (CVSS 7.7) vulnerability in Backstage: Configuration bypass in TechDocs mkdocs.yml sanitization. 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.

Published Oct 7, 2026Updated Oct 7, 2026Source checked Oct 7, 2026First seen by HOL Oct 7, 2026Material review Oct 7, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 7.7
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

CVSS is 7.7. 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.

Affected scope and exposure questions

The current feed maps backstage/backstage (generic), @backstage/plugin-techdocs-node (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
backstage/backstagegeneric	<1.50.5 \|\| >=1.51.0-next.0 <1.54.6	1.50.5, 1.54.6
@backstage/plugin-techdocs-nodegeneric	<1.14.6 \|\| >=1.15.0 <1.15.4	1.14.6, 1.15.4

Recommended response

Check inventory. Check lockfiles and deployed manifests for backstage/backstage, @backstage/plugin-techdocs-node.
Review the reported fix. Update backstage/backstage to 1.50.5; @backstage/plugin-techdocs-node to 1.14.6 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Oct 7, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Oct 7, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Oct 7, 2026

Sources and claim methodology

Upstream source description

Backstage is an open framework for building developer portals. Prior to 1.14.6, the @backstage/plugin-techdocs-node package is affected by configuration bypass in techdocs mkdocs.yml sanitization. Insufficient validation of MkDocs configuration during TechDocs generation could allow an authenticated user who can register or modify documentation sources to execute arbitrary commands in the build environment. Impact is limited to resources accessible to the TechDocs backend or build container. This issue is fixed in versions 1.14.6 and 1.15.4.

Quoted source text, attributed separately from HOL analysis.