CVE-2026-106458 Backstage: Inconsistent repository filtering in Bitbucket Server catalog event updates
Authenticated users can inject unauthorized repository locations into Backstage catalogs by exploiting inconsistent filtering in event-driven updates.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-106458?
CVE-2026-106458 is a medium-severity missing authorization vulnerability in Linuxfoundation Backstage, published on 6 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.
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.
Weakness: CWE-863
Which versions are affected by CVE-2026-106458?
2 open source packages ship an affected version, including @backstage/plugin-catalog-backend-module-bitbucket-server. It affects 2 products.
| Package | Affected | Fixed in |
|---|---|---|
@backstage/plugin-catalog-backend-module-bitbucket-server npm | From 0.4.0 | 0.5.15 |
@backstage/plugin-catalog-backend-module-bitbucket-server npm | From 0.4.0 | 0.5.15 |
Products include Linuxfoundation Backstage, Linuxfoundation Backstage\/Plugin-Catalog-Backend-Module-Bitbucket-Server.
How do I fix CVE-2026-106458?
Upgrade @backstage/plugin-catalog-backend-module-bitbucket-server to 0.5.15 or later.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-106458 being exploited?
There is no known exploitation of CVE-2026-106458 in the wild and no public exploit code.
Other vulnerabilities in Linuxfoundation Backstage
- CVE-2026-106501 Backstage: Sensitive information exposure in Scaffolder
- CVE-2026-106558 Backstage: Improper validation of TechDocs MkDocs configuration
- CVE-2026-88064 Backstage: Improper input validation in TechDocs MkDocs configuration
- CVE-2026-106459 Backstage: Improper input validation in Sentry scaffolder actions
- CVE-2026-106486 Backstage: Improper filesystem validation in Bitbucket pull-request scaffolder actions
Sources
Also known as GHSA-c36c-cf6r-ghgj.