CVE-2026-106558Backstage: Improper validation of TechDocs MkDocs configuration
Updated under an hour ago ()
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It affects backstage and 3 other products. Add what you run to find out whether that includes you.
EPSS puts the chance of exploitation in the next 30 days at 0.47%, higher than 39% of scored CVEs.
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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.
- CVSS
- 8.8 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Weakness (CWE)
- CWE-502
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- 0.47% (percentile 39)
- Assigned by
- GitHub_M
- NVD analysis
- Analyzed
- Record last updated
- Oct 10, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
backstage backstage backstage:backstage (from the name) | before 1.50.7; from 1.51.0-next.0, < 1.54.9; from 1.55.0-next.0, < 1.55.2 | CNA record |
@backstage plugin-techdocs-node backstage:plugin_techdocs_node (from the name) | before 1.14.8; from 1.15.0, < 1.15.6; from 2.0.0, < 2.0.1 | CNA record |
linuxfoundation backstage_plugin-techdocs-node linuxfoundation:backstage_plugin-techdocs-node | before 1.14.8; from 1.15.0 before 1.15.6; from 2.0.0 before 2.0.1 | NVD |
linuxfoundation backstage linuxfoundation:backstage | before 1.50.7; from 1.51.1 before 1.54.8; from 1.55.1 before 1.55.2; 1.51.0; 1.51.0; 1.51.0; 1.51.0; 1.51.0; and 4 more ranges | NVD |
References
- https://github.com/backstage/backstage/security/advisories/GHSA-qmw3-745m-w99gx-refsource-confirm, mitigation, vendor-advisory
- https://github.com/backstage/backstage/commit/32723a0fe4e12ed80535fc65d5331765c55aa91bx-refsource-misc, patch
- https://github.com/backstage/backstage/commit/944edb51c8524d3664b18f2d57ba101b1c93b709x-refsource-misc, patch
- https://github.com/backstage/backstage/commit/f18e9abcc6051491862b15e4fc60e69f8d52310cx-refsource-misc, patch
- https://github.com/backstage/backstage/releases/tag/v1.50.7x-refsource-misc, patch, release-notes
- https://github.com/backstage/backstage/releases/tag/v1.54.9x-refsource-misc, patch, release-notes
- https://github.com/backstage/backstage/releases/tag/v1.55.2x-refsource-misc, patch, release-notes
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.