CVE-2026-3960: Remote Code Execution in h2oai/h2o-3
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 Software
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Event History
Frequently Asked Questions
What is the severity of CVE-2026-3960?
CVE-2026-3960 has a critical severity rating due to its potential for remote code execution.
How do I fix CVE-2026-3960?
To fix CVE-2026-3960, upgrade H2O-3 to a version later than 3.46.0.9.
Which versions of H2O-3 are affected by CVE-2026-3960?
CVE-2026-3960 affects H2O-3 versions up to and including 3.46.0.9.
What types of attacks can exploit CVE-2026-3960?
CVE-2026-3960 can be exploited for remote code execution via the unauthenticated REST API endpoint /99/ImportSQLTable.
Is authentication required to exploit CVE-2026-3960?
No, CVE-2026-3960 can be exploited without authentication due to insufficient security controls.