A critical remote code execution vulnerability exists in the unauthenticated REST API endpoint /99/ImportSQLTable in H2O-3 version 3.46.0.9 and prior. The vulnerability arises due to insufficient security controls in the parameter blacklist mechanism, which only targets MySQL JDBC driver-specific dangerous parameters. An attacker can bypass these controls by switching the JDBC URL protocol to jdbc:postgresql: and exploiting PostgreSQL JDBC driver-specific parameters such as socketFactory and socketFactoryArg. This allows unauthenticated attackers to execute arbitrary code on the H2O-3 server with the privileges of the H2O-3 process. The issue is resolved in version 3.46.0.10.
Fix
Patch, vendor advisory and mitigation references on NVD 1
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 1
- First seenCVSS 9.8 · h2oNVD modified 2026-10-26 22:10
Affected (CPE criteria) 1
cpe:2.3:a:h2o:h2o:*:*:*:*:*:*:*:*
References 2
- https://github.com/h2oai/h2o-3/commit/b9ae2d3c5220db2dc53753357a783e590364d044 Patch
- https://huntr.com/bounties/6954fe04-b905-453f-8c53-205ac8377e0d Exploit, Third Party Advisory