CVE-2025-6544 CRITICAL

CVE-2025-6544: Deserialization Vulnerability in h2oai/h2o-3

Vendor H2Oai
Product h2oai/h2o-3
Weakness CWE-502 · Unsafe deserialization
Published September 21, 2025
Last update September 22, 2025

CVSS base score

9.8/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality High
Integrity High

CVSS vector

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

What the vulnerability does

01Description

A deserialization vulnerability exists in h2oai/h2o-3 versions <= 3.46.0.8, allowing attackers to read arbitrary system files and execute arbitrary code. The vulnerability arises from improper handling of JDBC connection parameters, which can be exploited by bypassing regular expression checks and using double URL encoding. This issue impacts all users of the affected versions.

Key dates

02Disclosure timeline

September 21, 2025 CVE published
September 22, 2025 Record updated