CVE-2026-106455: Backstage: Improper validation of MkDocs plugin configuration in TechDocs

Severity: high (CVSS 7.7 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-06 · updated 2026-10-13
Weakness: CWE-918

Description

Backstage is an open framework for building developer portals. From 0.11.12 until 1.14.7 and 1.15.5, the @backstage/plugin-techdocs-node package is affected by improper validation of mkdocs plugin configuration in techdocs. An authenticated attacker with control over a TechDocs source repository could cause a documentation build to retrieve and publish data from network locations reachable by the build environment. Exposure depends on deployment topology, build mode, and target endpoint protections. Modern cloud metadata services that require tokens or special headers are not directly accessible through the affected behavior. This issue is fixed in @backstage/plugin-techdocs-node versions 1.14.7 and 1.15.5.

Affected products

backstage: from 0.71.1 before 1.50.6; from 1.51.1 before 1.54.8; 1.51.0, 1.51.0-next0, 1.51.0-next1, 1.51.0-next2, 1.51.0-next3 — fixed in 1.50.6, 1.54.8
Linuxfoundation Backstage Plugin-Techdocs-Node: from 0.11.12 before 1.14.7; from 1.15.0 before 1.15.5 — fixed in 1.14.7, 1.15.5

How to fix

Upgrade to a fixed version: backstage 1.50.6, 1.54.8; Linuxfoundation Backstage Plugin-Techdocs-Node 1.14.7, 1.15.5. Check the vendor advisory for mitigations.

References

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