Backstage: Bypass of MkDocs configuration sanitizer in TechDocs backend

HIGH 8.5CVE-2026-106505 · GHSA-p75x-jh7p-ppcx · Published 06/10/2026 · updated 09/10/2026

Package	Affected versions	Patched versions
backstage linuxfoundation	`= 1.51.0≥ 1.51.1, < 1.54.6< 1.50.5`	`1.54.61.50.5`
backstage plugin-techdocs-node linuxfoundation	`≥ 1.15.0, < 1.15.4< 1.14.6`	`1.15.41.14.6`
@backstage/plugin-techdocs-node npm	`< 1.15.4`	`1.15.4`

Description

Impact

Users with the ability to commit changes to a repository that uses TechDocs can circumvent the MkDocs configuration file sanitizer introduced in response to CVE-2026-25153 and execute arbitrary code on the TechDocs backend host during documentation generation.

Patches

Patched in@backstage/plugin-techdocs-node version 1.15.4

Workarounds

If you cannot upgrade immediately:

Use Docker mode with restricted access: Configure TechDocs with runIn: docker instead of runIn: local. This provides container isolation, though it does not fully mitigate the risk.
Limit repository write access to trusted parties, since exploitation requires the ability to commit files to a repository with TechDocs enabled.
Review incoming changes to MkDocs configuration files as part of your code review process.

NVD description

Backstage is an open framework for building developer portals. Prior to 1.14.6 and 1.15.4, the @backstage/plugin-techdocs-node package is affected by bypass of mkdocs configuration sanitizer in techdocs backend. Users with the ability to commit changes to a repository that uses TechDocs can circumvent the MkDocs configuration file sanitizer introduced in response to CVE-2026-25153 and execute arbitrary code on the TechDocs backend host during documentation generation. This issue is fixed in versions 1.14.6 and 1.15.4.

References

backstage/backstage security advisory · WEB
nvd.nist.gov/vuln/detail/CVE-2026-106505 · ADVISORY
backstage/backstage commit a7d995f · WEB
backstage/backstage commit ef92d3d · WEB
backstage/backstage · PACKAGE
backstage/backstage release v1.50.5 · WEB
backstage/backstage release v1.54.6 · WEB

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Package

Affected versions

Patched versions

backstage

linuxfoundation

= 1.51.0≥ 1.51.1, < 1.54.6< 1.50.5

1.54.61.50.5

backstage plugin-techdocs-node

linuxfoundation

≥ 1.15.0, < 1.15.4< 1.14.6

1.15.41.14.6

@backstage/plugin-techdocs-node

npm

< 1.15.4

1.15.4

Description

Impact

Patches

Patched in@backstage/plugin-techdocs-node version 1.15.4

Workarounds

If you cannot upgrade immediately:

Use Docker mode with restricted access: Configure TechDocs with runIn: docker instead of runIn: local. This provides container isolation, though it does not fully mitigate the risk.
Limit repository write access to trusted parties, since exploitation requires the ability to commit files to a repository with TechDocs enabled.
Review incoming changes to MkDocs configuration files as part of your code review process.

NVD description