CVE-2026-106458: backstage Incorrect Authorization

Vulnerability summary

CVE-2026-106458 is a medium (CVSS 6.5) Incorrect Authorization vulnerability in backstage. EPSS estimates a 0.27% chance of exploitation in the next 30 days, higher than 17.8% of scored vulnerabilities.

Timeline

1. 06-10-2026
   PublishedVulnerability first disclosed.
2. 07-10-2026
   Last modifiedVulnerability information updated.

Description

Backstage is an open framework for building developer portals. From 0.4.0 until 0.5.15, the @backstage/plugin-catalog-backend-module-bitbucket-server package is affected by inconsistent repository filtering in bitbucket server catalog event updates. Deployments using event-driven updates in the Bitbucket Server catalog provider may ingest catalog locations from repositories that are excluded by the provider's configured project, repository, or archived-repository filters. An authenticated Bitbucket Server user who can push to a filtered-out repository that remains readable by the configured Backstage integration can trigger a legitimate repository event. The affected event path may then add a Location for that repository even though scheduled discovery excludes it. This issue is fixed in version 0.5.15.

• CWE-863Incorrect AuthorizationThe product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.