CVE-2026-3960

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.

CVSS v3 9.8 CRITICAL

9.8^/10

CVSS v3 : CRITICAL

Vector :

Exploitability : 3.9 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://github.com/h2oai/h2o-3/commit/b9ae2d3c5220db2dc53753357a783e590364d044	Patch
https://huntr.com/bounties/6954fe04-b905-453f-8c53-205ac8377e0d	Exploit Third Party Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:h2o:h2o:*:*:*:*:*:*:*:*

History

19 May 2026, 21:52

Type	Values Removed	Values Added
CVSS	v2 : ~~unknown~~ v3 : ~~5.9~~	v2 : unknown v3 : 9.8
CPE		cpe:2.3:a:h2o:h2o::::::::
References	~~() https://github.com/h2oai/h2o-3/commit/b9ae2d3c5220db2dc53753357a783e590364d044 -~~	() https://github.com/h2oai/h2o-3/commit/b9ae2d3c5220db2dc53753357a783e590364d044 - Patch
References	~~() https://huntr.com/bounties/6954fe04-b905-453f-8c53-205ac8377e0d -~~	() https://huntr.com/bounties/6954fe04-b905-453f-8c53-205ac8377e0d - Exploit, Third Party Advisory
First Time		H2o H2o h2o

23 Apr 2026, 10:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-04-23 10:16

Updated : 2026-05-19 21:52

NVD link : CVE-2026-3960

Mitre link : CVE-2026-3960

CVE.ORG link : CVE-2026-3960

JSON object : View

Products Affected

h2o

h2o

CWE

CWE-94

Improper Control of Generation of Code ('Code Injection')

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