GHSA-h376-j262-vhq6
CRITICALGHSA-h376-j262-vhq6 is a critical-severity (CVSS 9.8) Deserialization of Untrusted Data vulnerability in com.h2database:h2. 2 public exploit references exist, so weaponization risk is real. O3 Security confirms whether GHSA-h376-j262-vhq6 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
RCE in H2 Console
Real-World Exposure
com.h2database:h2Real-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
Impact
H2 Console in versions since 1.1.100 (2008-10-14) to 2.0.204 (2021-12-21) inclusive allows loading of custom classes from remote servers through JNDI.
H2 Console doesn't accept remote connections by default. If remote access was enabled explicitly and some protection method (such as security constraint) wasn't set, an intruder can load own custom class and execute its code in a process with H2 Console (H2 Server process or a web server with H2 Console servlet).
It is also possible to load them by creation a linked table in these versions, but it requires ADMIN privileges and user with ADMIN privileges has full access to the Java process by design. These privileges should never be granted to untrusted users.
Patches
Since version 2.0.206 H2 Console and linked tables explicitly forbid attempts to specify LDAP URLs for JNDI. Only local data sources can be used.
Workarounds
H2 Console should never be available to untrusted users.
-webAllowOthers is a dangerous setting that should be avoided.
H2 Console Servlet deployed on a web server can be protected with a security constraint:
https://h2database.com/html/tutorial.html#usingH2ConsoleServlet
If webAllowOthers is specified, you need to uncomment and edit <security-role> and <security-constraint> as necessary. See documentation of your web server for more details.
References
This issue was found and privately reported to H2 team by JFrog Security's vulnerability research team with detailed information.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | com.h2database:h2 | ≥ 1.1.100&&< 2.0.206 | 2.0.206 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for com.h2database:h2. 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 com.h2database:h2 to 2.0.206 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-h376-j262-vhq6 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-h376-j262-vhq6 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-h376-j262-vhq6. 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-h376-j262-vhq6 in your dependencies?
O3 detects GHSA-h376-j262-vhq6 across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.