Disclosure summary
### Impact An authenticated Backstage user could craft a catalog entity with placeholder directives that reference resources outside the entity's source repository. Under certain configurations, this could allow access to data not intended to be available to the user. ### Patches Patched in `@backstage/plugin-catalog-backend` version `3.9.1` ### Workarounds If you're not able to update immediately: - Limit the scope of integration credentials (e.g., GitHub tokens) to only the repositories that Backstage needs to access.
Source-specific records & product guidance
Sources retain their own attribution and scoring. Follow the original record to confirm affected versions, fixed releases, and configuration conditions.
GitHub Reviewed Security Advisories · GHSA-qgvj-qcf8-xq73
Open original source · Updated Oct 07, 2026
Backstage: Improper URL validation in catalog entity placeholder resolution
Source severity: HIGH / 0
| Ecosystem | Package | Affected range | First patched |
|---|---|---|---|
| npm | @backstage/plugin-catalog-backend | < 3.9.1 | 3.9.1 |
Original records & references
- NIST NVD record
- CVE Program record
- github.com — Reviewed advisory
PUBLISHED 2026-10-07T13:59:24-04:00
MODIFIED 2026-10-07T13:59:29-04:00
INGESTED 2026-10-08T12:30:38-04:00