All vulnerabilities
CVE-2025-6544GHSA-5w3j-gwgh-4rfvPYSEC-2026-349

ai.h2o:h2o-core: H2O affected by a deserialization vulnerability

h2oai ai.h2o:h2o-coremavenLibraries & packages
Open in ThreatlineRecord JSON
CVSS
9.8Critical
ExploitationPublic exploit codeCISA's assessment says proof of concept code is public, assessed 22 Sep 2025. Not in the KEV catalogCISA via CVE List
Exploit odds (EPSS)0.92%Chance of exploitation activity in the next 30 days, higher than 60% of CVEs. Scored 27 Oct 2026FIRST EPSS
Fixed in3.46.8Fixed versionCVE List
Published21 Sep 2025Updated 27 Oct 2026CVE List

What fixes it

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

Description

A deserialization vulnerability exists in h2oai/h2o-3 versions <= 3.46.0.7, 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.

Text from CVE List

Affected versions 105

  • ai.h2o:h2o-core, maven<= 3.46.0.7GitHub
  • h2o, pip<= 3.46.0.7GitHub
  • h2oai/h2o-3affected: unspecified before 3.46.8CVE List
  • ai.h2o:h2o-core, Mavenfrom first release, through 3.46.0.7OSV
  • ai.h2o:h2o-core, Maven0.1.10OSV
  • ai.h2o:h2o-core, Maven0.1.11OSV
  • ai.h2o:h2o-core, Maven0.1.12OSV
  • ai.h2o:h2o-core, Maven0.1.13OSV
  • ai.h2o:h2o-core, Maven0.1.14OSV
  • ai.h2o:h2o-core, Maven0.1.15OSV
  • ai.h2o:h2o-core, Maven0.1.16OSV
  • ai.h2o:h2o-core, Maven0.1.17OSV
  • ai.h2o:h2o-core, Maven0.1.18OSV
  • ai.h2o:h2o-core, Maven0.1.19OSV
  • ai.h2o:h2o-core, Maven0.1.20OSV
  • ai.h2o:h2o-core, Maven0.1.21OSV
  • ai.h2o:h2o-core, Maven0.1.22OSV
  • ai.h2o:h2o-core, Maven0.1.23OSV
  • ai.h2o:h2o-core, Maven0.1.24OSV
  • ai.h2o:h2o-core, Maven0.1.25OSV
  • ai.h2o:h2o-core, Maven0.1.3OSV
  • ai.h2o:h2o-core, Maven0.1.3.1OSV
  • ai.h2o:h2o-core, Maven0.1.4OSV
  • ai.h2o:h2o-core, Maven0.1.5OSV
  • ai.h2o:h2o-core, Maven0.1.6OSV
  • ai.h2o:h2o-core, Maven0.1.8OSV
  • ai.h2o:h2o-core, Maven0.1.9OSV
  • ai.h2o:h2o-core, Maven0.2.3.5OSV
  • ai.h2o:h2o-core, Maven0.2.3.6OSV
  • ai.h2o:h2o-core, Maven0.3.0.2OSV
  • ai.h2o:h2o-core, Maven3.0.0.12OSV
  • ai.h2o:h2o-core, Maven3.0.0.16OSV
  • ai.h2o:h2o-core, Maven3.0.0.18OSV
  • ai.h2o:h2o-core, Maven3.0.0.19OSV
  • ai.h2o:h2o-core, Maven3.0.0.22OSV
  • ai.h2o:h2o-core, Maven3.0.0.25OSV
  • ai.h2o:h2o-core, Maven3.0.0.26OSV
  • ai.h2o:h2o-core, Maven3.0.0.30OSV
  • ai.h2o:h2o-core, Maven3.0.0.5OSV
  • ai.h2o:h2o-core, Maven3.0.0.8OSV
  • ai.h2o:h2o-core, Maven3.0.1.2OSV
  • ai.h2o:h2o-core, Maven3.0.1.3OSV
  • ai.h2o:h2o-core, Maven3.0.1.4OSV
  • ai.h2o:h2o-core, Maven3.10.0.1OSV
  • ai.h2o:h2o-core, Maven3.10.0.10OSV
  • ai.h2o:h2o-core, Maven3.10.0.2OSV
  • ai.h2o:h2o-core, Maven3.10.0.3OSV
  • ai.h2o:h2o-core, Maven3.10.0.4OSV
  • ai.h2o:h2o-core, Maven3.10.0.5OSV
  • ai.h2o:h2o-core, Maven3.10.0.6OSV
  • ai.h2o:h2o-core, Maven3.10.0.7OSV
  • ai.h2o:h2o-core, Maven3.10.0.8OSV
  • ai.h2o:h2o-core, Maven3.10.0.9OSV
  • ai.h2o:h2o-core, Maven3.10.1.1OSV
  • h2o, PyPIfrom first release, through 3.46.0.7OSV
  • h2o, PyPI3.10.0.10OSV
  • h2o, PyPI3.10.0.3OSV
  • h2o, PyPI3.10.0.6OSV
  • h2o, PyPI3.10.0.7OSV
  • h2o, PyPI3.10.0.8OSV
  • h2o, PyPI3.10.3.3OSV
  • h2o, PyPI3.10.3.4OSV
  • h2o, PyPI3.10.4.1OSV
  • h2o, PyPI3.10.4.2OSV
  • h2o, PyPI3.10.4.3OSV
  • h2o, PyPI3.10.4.4OSV
  • h2o, PyPI3.10.4.6OSV
  • h2o, PyPI3.10.4.8OSV
  • h2o, PyPI3.16.0.1OSV
  • h2o, PyPI3.16.0.2OSV
  • h2o, PyPI3.16.0.3OSV
  • h2o, PyPI3.16.0.4OSV
  • h2o, PyPI3.18.0.1OSV
  • h2o, PyPI3.18.0.10OSV
  • h2o, PyPI3.18.0.11OSV
  • h2o, PyPI3.18.0.2OSV
  • h2o, PyPI3.18.0.3OSV
  • h2o, PyPI3.18.0.4OSV
  • h2o, PyPI3.18.0.5OSV
  • h2o, PyPI3.18.0.6OSV
  • h2o, PyPI3.18.0.7OSV
  • h2o, PyPI3.18.0.8OSV
  • h2o, PyPI3.18.0.9OSV
  • h2o, PyPI3.20.0.4OSV
  • h2o, PyPI3.20.0.5OSV
  • h2o, PyPI3.20.0.6OSV
  • h2o, PyPI3.20.0.7OSV
  • h2o, PyPI3.20.0.8OSV
  • h2o, PyPI3.22.0.1OSV
  • h2o, PyPI3.22.0.2OSV
  • h2o, PyPI3.22.0.3OSV
  • h2o, PyPI3.22.0.4OSV
  • h2o, PyPI3.22.0.5OSV
  • h2o, PyPI3.22.1.1OSV
  • h2o, PyPI3.22.1.2OSV
  • h2o, PyPI3.22.1.3OSV
  • h2o, PyPI3.22.1.4OSV
  • h2o, PyPI3.22.1.5OSV
  • h2o, PyPI3.22.1.6OSV
  • h2o, PyPI3.24.0.1OSV
  • h2o, PyPI3.24.0.2OSV
  • h2o, PyPI3.24.0.3OSV
  • h2o, PyPI3.24.0.4OSV
  • h2o, PyPI3.24.0.5OSV
  • h2o, PyPI3.26.0.1OSV

References 6