CVE-2026-106490: Backstage: Improper input validation in TechDocs static content requests

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-06 · updated 2026-10-22
Weakness: CWE-22

Description

Backstage is an open framework for building developer portals. Prior to 2.2.4, the @backstage/plugin-techdocs-backend package is affected by improper input validation in techdocs static content requests. When using the Azure Blob Storage provider, an authenticated Backstage user may be able to read restricted TechDocs content when entity-level permissions are enabled. Deployments that intentionally disable the default backend authentication policy may have broader exposure. This issue is fixed in version 2.2.4.

Affected products

backstage: before 1.54.6 — fixed in 1.54.6
Linuxfoundation Backstage/Plugin-Techdocs-Backend: before 2.2.4 — fixed in 2.2.4

How to fix

Upgrade to a fixed version: backstage 1.54.6; Linuxfoundation Backstage/Plugin-Techdocs-Backend 2.2.4. Check the vendor advisory for mitigations.

References

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