Deserialization in H2oai H2oai/h2o-3

CVE-2025-6507

A vulnerability in the h2oai/h2o-3 repository allows attackers to exploit deserialization of untrusted data, potentially leading to arbitrary code execution and reading of system files. This issue affects the latest master branch version 3.47.0.99999. The vulnerability arises from the ability to bypass regular expression filters intended to prevent malicious parameter injection in JDBC connections. Attackers can manipulate spaces between parameters to evade detection, allowing for unauthorized file access and code execution. The vulnerability is addressed in version 3.46.0.8.

Vulnerability class: Insecure Deserialization

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.144 (96.5th percentile), scored .

Moderate probability of exploitation in the next 30 days — watch for active exploitation reports. 97th percentile — 96.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-6507: rose from 0.137 to 0.144.

EPSS over last 30 days · oldest: 0.137 · newest: 0.144 · change: +0.007

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-6507?
CVE-2025-6507 is a critical-severity vulnerability in H2oai H2oai/h2o-3, classified under Deserialization of Untrusted Data. CVSS score: 9.8/10. Published 2025-09-01.
How severe is CVE-2025-6507?
Critical severity. CVSS v3 base score is 9.8 out of 10.