GHSA-qmc2-jpr5-7rg9
MEDIUMBackstage Scaffolder plugin vulnerable to Server-Side Request Forgery
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-scaffolder-node📦@backstage/plugin-scaffolder-node📦@backstage/plugin-scaffolder-nodeReal-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 is identified in Backstage Scaffolder template functionality where Server-Side Template Injection (SSTI) can be exploited to perform Git config injection. The vulnerability allows an attacker to capture privileged git tokens used by the Backstage Scaffolder plugin. With these tokens, unauthorized access to sensitive resources in git can be achieved. The impact is considered medium severity as the Backstage Threat Model recommends restricting access to adding and editing templates in the Backstage Catalog plugin.
Patches
The issue has been resolved in versions v0.4.12, v0.5.1 and v0.6.1 of the @backstage/plugin-scaffolder-node package. Users are encouraged to upgrade to this version to mitigate the vulnerability.
Workarounds
Users can ensure that templates do not change git config.
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-scaffolder-node | all versions | 0.4.12 |
| 📦npm | @backstage/plugin-scaffolder-node | ≥ 0.5.0&&< 0.5.1 | 0.5.1 |
| 📦npm | @backstage/plugin-scaffolder-node | ≥ 0.6.0&&< 0.6.1 | 0.6.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @backstage/plugin-scaffolder-node. 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-scaffolder-node to 0.4.12 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-qmc2-jpr5-7rg9 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-qmc2-jpr5-7rg9 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-qmc2-jpr5-7rg9. 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-qmc2-jpr5-7rg9 in your dependencies?
O3 detects GHSA-qmc2-jpr5-7rg9 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.