CVE-2024-5986: h2oai h2oai/h2o-3

Critical severity, CVSS 9.1. EPSS: 0.7% chance of exploitation in the next 30 days.

A vulnerability in h2oai/h2o-3 version 3.46.0.1 allows remote attackers to write arbitrary data to any file on the server. This is achieved by exploiting the `/3/Parse` endpoint to inject attacker-controlled data as the header of an empty file, which is then exported using the `/3/Frames/framename/export` endpoint. The impact of this vulnerability includes the potential for remote code execution and complete access to the system running h2o-3, as attackers can overwrite critical files such as private SSH keys or script files.

Affected products

• h2oai h2oai/h2o-3: affected versions not specified

Published 2026-02-02. Last modified 2026-06-17.