GHSA-5pq9-5mpr-jj85
MEDIUMJervis Has a JWT Algorithm Confusion Vulnerability
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
net.gleske:jervisReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
Description
Vulnerability
The code doesn't validate that the JWT header specifies "alg":"RS256".
Impact
Depending on the broader system, this could allow JWT forgery.
Internally this severity is low since JWT is only intended to interface with GitHub. External users should consider severity moderate.
Patches
Jervis patch will explicitly verify the algorithm in the header matches expectations and further verify the JWT structure.
Upgrade to Jervis 2.2.
Workarounds
External users should consider using an alternate JWT library or upgrade.
References
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | net.gleske:jervis | all versions | 2.2 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for net.gleske:jervis. 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 net.gleske:jervis to 2.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-5pq9-5mpr-jj85 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-5pq9-5mpr-jj85 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-5pq9-5mpr-jj85. 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-5pq9-5mpr-jj85 in your dependencies?
O3 detects GHSA-5pq9-5mpr-jj85 across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.