CVE-2025-6544

UNKNOWN

Published Unknown

Actions:

Expert Analysis

Professional remediation guidance

Get tailored security recommendations from our analyst team for CVE-2025-6544. We'll provide specific mitigation strategies based on your environment and risk profile.

No CVSS data available

Description

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.

Available Exploits

No exploits available for this CVE.

Related News

No news articles found for this CVE.

EU Vulnerability Database

Monitored by ENISA for EU cybersecurity

EU Coordination

EU Coordinated

Exploitation Status

No Known Exploitation

EUVD ID

View on ENISA

ENISA Analysis

Malicious code in bioql (PyPI)

Affected Products (ENISA)

h2oai

h2oai/h2o-3

ENISA Scoring

CVSS Score (3.0)

9.8

/10

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Score

0.100

probability

ENISA References

https://huntr.com/bounties/53f35a0f-d644-4f82-93aa-89fe7e0aed40

https://github.com/h2oai/h2o-3/commit/0298ee348f5c73673b7b542158081e79605f5f25

https://nvd.nist.gov/vuln/detail/CVE-2025-6544

Data provided by ENISA EU Vulnerability Database. Last updated: October 3, 2025

GitHub Security Advisories

Community-driven vulnerability intelligence from GitHub

✓ GitHub Reviewed CRITICAL

H2O affected by a deserialization vulnerability

GHSA-5w3j-gwgh-4rfv

Advisory Details

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.

Affected Packages

Maven ai.h2o:h2o-core

ECOSYSTEM: ≥0 ≤3.46.0.7

PyPI h2o

ECOSYSTEM: ≥0 ≤3.46.0.7

CVSS Scoring

CVSS Score

9.0

CVSS Vector


                                    CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References

ADVISORY https://nvd.nist.gov/vuln/detail/CVE-2025-6544

WEB https://github.com/h2oai/h2o-3/commit/0298ee348f5c73673b7b542158081e79605f5f25

PACKAGE https://github.com/h2oai/h2o-3

WEB https://huntr.com/bounties/53f35a0f-d644-4f82-93aa-89fe7e0aed40

Advisory provided by GitHub Security Advisory Database. Published: September 22, 2025, Modified: September 22, 2025

Published: Unknown

Last Modified: Unknown

Copied to clipboard!