CVE-2026-106509
Backstage: Improper validation of MkDocs theme configuration in TechDocs
CVSS Score
7.7
EPSS Score
0.0%
EPSS Percentile
0th
Backstage is an open framework for building developer portals. Prior to 1.14.6, the @backstage/plugin-techdocs-node package is affected by improper validation of mkdocs theme configuration in techdocs. When TechDocs is configured to build documentation locally or in a container, a user with write access to a registered repository can include configuration values in mkdocs.yml that cause arbitrary code execution during the documentation build process. This issue is fixed in versions 1.14.6 and 1.15.4.
| CWE | CWE-94 CWE-1336 |
| Vendor | backstage |
| Product | backstage |
| Published | Oct 6, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:L Attack Vector
Network
Attack Complexity
High
Privileges Required
Low
User Interaction
None
Scope
Changed
Confidentiality
High
Integrity
Low
Availability
Low
Affected Versions
backstage / backstage
< 1.50.5 >= 1.51.0-next.0, < 1.54.6
@backstage / plugin-techdocs-node
< 1.14.6 >= 1.15.0, < 1.15.4
References
github.com: https://github.com/backstage/backstage/security/advisories/GHSA-8w7q-29mw-gf5c github.com: https://github.com/backstage/backstage/commit/02cd7cdbb18b687446277b5602adaee7f1d53cbb github.com: https://github.com/backstage/backstage/commit/a900a9953c8f7ad3ba1906d1d257725a9996cc9d github.com: https://github.com/backstage/backstage/releases/tag/v1.50.5 github.com: https://github.com/backstage/backstage/releases/tag/v1.54.6