GHSA-gxp5-mv27-vjcj
HIGHJervis's AES CBC Mode is Without Authentication
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
AES/CBC/PKCS5Padding lacks authentication, making it vulnerable to padding oracle attacks and ciphertext manipulation.
Impact
Severity is considered low for internal uses of this library but if there's any consumer using these methods directly then this is considered critical.
Unlikely to matter due to the design of how AES-256-CBC is used in conjunction with RSA and SHA-256 checksum within Jervis.
Jervis uses RSA to encrypt AES keys and a SHA-256 checksum of the encrypted data in local-only storage inaccessible from the web. After asymmetric decryption and before symmetric decryption, a SHA-256 checksum is performed on the metadata and encrypted data. All encrypted data is discarded if the checksum does not match without attempting to decrypt since the encrypted data is assumed invalid. The data stored is GitHub App authentication tokens which will expire within one hour.
Patches
Jervis patch will migrate from AES/CBC/PKCS5Padding to AES/GCM/NoPadding.
Upgrade to Jervis 2.2.
Workarounds
None
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-gxp5-mv27-vjcj 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-gxp5-mv27-vjcj 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-gxp5-mv27-vjcj. 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-gxp5-mv27-vjcj in your dependencies?
O3 detects GHSA-gxp5-mv27-vjcj across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.