H2O-3PYSEC-2026-2180
H2O-3: remote code execution
Fix: upgrade to 3.46.0.10 or later
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.
Affected versions
| Package | Affected | Fixed in |
|---|---|---|
| h2o PyPI | < 3.46.0.10 | 3.46.0.10 |
Details and references
- CVSS 3.1
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Severity from
- the CVSS score
- Also known as
- CVE-2026-3960, GHSA-qmcv-hh7c-3m56