CVE-2025-6544

published 2025-09-21

CVE-2025-6544: 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…

Priority P2 63 critical 9.8 CVSS 3.0

AV N AC L PR N UI N S U C H I H A H

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.

Affected

3 ranges

Vendor	Product	Version range	Fixed in
h2o	h2o	0 – 3.46.0.7	—
h2o	h2o	3.0.0.2 – 3.46.0.8	—
h2oai	h2oai_h2o-3	>= unspecified < 3.46.8	3.46.8

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