CVE-2025-6544

CRITICAL

h2o-3 <= 3.46.0.8 - Open Redirect

Title source: llm

Description

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.

Scores

CVSS v3 9.8
EPSS 0.0042
EPSS Percentile 61.8%
Attack Vector NETWORK
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Classification

CWE
CWE-502
Status published

Affected Products (3)

h2o/h2o < 3.46.0.8
ai.h2o/h2o-core Maven
pypi/h2o PyPI

Timeline

Published Sep 21, 2025
Tracked Since Feb 18, 2026