CVE-2026-106558
Description
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.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
Propose a mitigation on Community Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
References
- https://github.com/backstage/backstage/commit/32723a0fe4e12ed80535fc65d5331765c55aa91b
- https://github.com/backstage/backstage/commit/944edb51c8524d3664b18f2d57ba101b1c93b709
- https://github.com/backstage/backstage/commit/f18e9abcc6051491862b15e4fc60e69f8d52310c
- https://github.com/backstage/backstage/releases/tag/v1.50.7
- https://github.com/backstage/backstage/releases/tag/v1.54.9
- https://github.com/backstage/backstage/releases/tag/v1.55.2
- https://github.com/backstage/backstage/security/advisories/GHSA-qmw3-745m-w99g
CWEs
CWE-502
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.