High 7.7Published Oct 6, 2026

CVE-2026-106509Backstage: Improper validation of MkDocs theme configuration in TechDocs

Updated under an hour ago (Oct 28, 2026, 2:10 PM ET)

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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 0.37%, higher than 29% of scored CVEs.

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Every CVE for backstage

Exploited in the last 30 days

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.

CVSS: 7.7 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:L
Weakness (CWE): CWE-94, CWE-1336
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): 0.37% (percentile 29)
Assigned by: GitHub_M
NVD analysis: Analyzed
Record last updated: Oct 7, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

backstage backstage backstage:backstage (from the name)	before 1.50.5; from 1.51.0-next.0, < 1.54.6	CNA record
@backstage plugin-techdocs-node backstage:plugin_techdocs_node (from the name)	before 1.14.6; from 1.15.0, < 1.15.4	CNA record
linuxfoundation backstage_plugin-techdocs-node linuxfoundation:backstage_plugin-techdocs-node	before 1.14.6; from 1.15.0 before 1.15.4	NVD
linuxfoundation backstage linuxfoundation:backstage	before 1.50.5; from 1.51.1 before 1.54.6; 1.51.0; 1.51.0; 1.51.0; 1.51.0; 1.51.0	NVD

References

References

https://github.com/backstage/backstage/security/advisories/GHSA-8w7q-29mw-gf5c	x-refsource-confirm, vendor-advisory, mitigation
https://github.com/backstage/backstage/commit/02cd7cdbb18b687446277b5602adaee7f1d53cbb	x-refsource-misc, exploit, patch
https://github.com/backstage/backstage/commit/a900a9953c8f7ad3ba1906d1d257725a9996cc9d	x-refsource-misc, exploit, patch
https://github.com/backstage/backstage/releases/tag/v1.50.5	x-refsource-misc, release-notes
https://github.com/backstage/backstage/releases/tag/v1.54.6	x-refsource-misc, 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.