GHSA-f8j4-p5cr-p777
MEDIUMPermission policy information leakage in Backstage permission system
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
@backstage/plugin-permission-backendReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects npm packages — download data is not available via public APIs for these ecosystems.
Description
Impact
A vulnerability in the Backstage permission plugin backend allows callers to extract some information about the conditional decisions returned by the permission policy installed in the permission backend. If the permission system is not in use or if the installed permission policy does not use conditional decisions, there is no impact.
Patches
This issue has been resolved in version 0.6.0 of the permissions backend.
Workarounds
Administrators of the permission policies can ensure that they are crafted in such a way that conditional decisions do not contain any sensitive information.
References
If you have any questions or comments about this advisory:
Open an issue in the Backstage repository Visit our Discord, linked to in Backstage README
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @backstage/plugin-permission-backend | all versions | 0.6.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @backstage/plugin-permission-backend. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update @backstage/plugin-permission-backend to 0.6.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-f8j4-p5cr-p777 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-f8j4-p5cr-p777 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-f8j4-p5cr-p777. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-f8j4-p5cr-p777 in your dependencies?
O3 detects GHSA-f8j4-p5cr-p777 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.