Vulnerability · Published Oct 6, 2026 · Assigned by GitHub_M

CVE-2026-106458Backstage: Inconsistent repository filtering in Bitbucket Server catalog event updates

Medium 6.5

In plain English

A medium-severity incorrect authorization in backstage from backstage. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 19% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)6.5Medium
Exploit odds (30 days)0.3%top 80.9% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
npm@backstage/plugin-catalog-backend-module-bitbucket-server0.5.15GHSA-c36c-cf6r-ghgj

Affected products (as reported)

VendorProductVersions
backstage backstage >= 1.38.0, < 1.55.0
@backstage plugin-catalog-backend-module-bitbucket-server >= 0.4.0, < 0.5.15

Weakness: CWE-863 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

References