BaselineWatch
Desk

CVE-2026-3960

9.8 critical SSVC exploitation: poc Analyzed

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

  1. First seenCVSS 9.8 · h2oNVD modified 2026-10-26 22:10

Affected (CPE criteria) 1

  • cpe:2.3:a:h2o:h2o:*:*:*:*:*:*:*:*

References 2