CVE-2026-8751: h2o-3 JAR Handler Import Vulnerability to Remote Deserialization

Summary

An attacker can remotely exploit a security flaw in h2o-3's JAR Handler, allowing them to potentially take control of your system. This affects versions up to 7402. We recommend updating to the latest version as soon as possible.

What to do

No fix is available yet. Check with your software vendor for updates.

Affected software

Vendor	Product	Affected versions
h2o	h2o	<= 7402 `cpe:2.3:a:h2o:h2o::::::::`

Original title

A security flaw has been discovered in h2oai h2o-3 up to 7402. This affects the function importBinaryModel of the file h2o-core/src/main/java/hex/Model.java of the component JAR Handler. Performing...

Original description

A security flaw has been discovered in h2oai h2o-3 up to 7402. This affects the function importBinaryModel of the file h2o-core/src/main/java/hex/Model.java of the component JAR Handler. Performing a manipulation results in deserialization. The attack is possible to be carried out remotely. The exploit has been released to the public and may be used for attacks. The vendor was contacted early about this disclosure but did not respond in any way.

nvd CVSS2.0 7.5

nvd CVSS3.1 7.3

nvd CVSS4.0 5.5

Vulnerability type

CWE-20 Improper Input Validation

CWE-502 Deserialization of Untrusted Data