Read the docs
TI-2025-05944 Aliases CVE-2025-6544GHSA-5w3j-gwgh-4rfv

Deserialization Vulnerability in h2oai/h2o-3

Priority HIGH 82CWE-502Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 3.0 · CNA. Fix status from CNA and GitHub. Impact type from CWE-502.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00952 61st percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed h2oai/h2o-3 (h2oai): 3.46.8

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
Yes
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
h2oaih2oai/h2o-3before 3.46.83.46.8Patch availableCNA
—ai.h2o:h2o-core (Maven)up to 3.46.0.7—No fix listedGHSA-5w3j-gwgh-4rfv
—h2o (PyPI)up to 3.46.0.7—No fix listedGHSA-5w3j-gwgh-4rfv
  • h2oai/h2o-3 Vendorh2oai Affected before 3.46.8 Fixed in 3.46.8 Patch available CNA
  • ai.h2o:h2o-core (Maven) Vendor— Affected up to 3.46.0.7 Fixed in — No fix listed GHSA-5w3j-gwgh-4rfv
  • h2o (PyPI) Vendor— Affected up to 3.46.0.7 Fixed in — No fix listed GHSA-5w3j-gwgh-4rfv

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:h2o:h2o:*:*:*:*:*:*:*:*3.0.0.2 – 3.46.0.8Vulnerableh2oai
  • cpe:2.3:a:h2o:h2o:*:*:*:*:*:*:*:* Versions 3.0.0.2 – 3.46.0.8 Vulnerable ·h2oai

Remediation

  • Fix · CNA h2oai/h2o-3 (h2oai) Fixed in 3.46.8

Timeline

  1. 2026-10-02 Threatist record created from CVE-2025-6544
  2. 2026-10-03 Alias added: GHSA-5w3j-gwgh-4rfv

References

Exploit 1

Patch 1

Advisory 1

Other 3

  • TI-2024-09776 Jdbc Deserialization in h2oai/h2o-3 CVSS 3.0CRITICAL 9.8
  • TI-2024-30727 H2O.ai H2O through 3.46.0.4 allows attackers to arbitrarily set the JDBC URL, leading to… CVSS 3.1CRITICAL 9.1
  • TI-2026-03424 Remote Code Execution in h2oai/h2o-3 CVSS 3.1CRITICAL 9.8
  • TI-2024-07992 Arbitrary File Overwrite in h2oai/h2o-3 CVSS 3.0HIGH 8.2
  • TI-2023-06020 External Control of File Name or Path in h2oai/h2o-3 CVSS 3.1HIGH 8.2
  • TI-2024-09794 Denial of Service and Arbitrary File Write in h2oai/h2o-3 CVSS 3.0HIGH 7.5
See all 29 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences