CVE-2025-6544

criticalpriority · track · 0EPSS 0.009 · 60 %ileEURUUS

grimoire priorityP2 · Scheduled

Exploitable?

—

no known exploitation

Likely / severe?

0.92% (60th) EPSS

CVSS 9.8 · critical

Is it mine?

5 products

Check your exposure

Who says so?

5 sources

cnnvd · enisa_euvd · fstec_bdu · osv

EPSS · scored 2026-10-27

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.

cvss

Technical severity, 0–10. One row per scoring source.

9.8

010

base score 0–10 · higher = more severe · hover a vector to decode

v3.09.8criticalCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsecondary · ENISA EU

v3.09.8criticalCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsecondary · security@huntr.devexploitability 3.9 · impact 5.9

v3.09.8criticalCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsecondary · OSV

v3.19.8criticalAV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsecondary · FSTEC (BDU) RU

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: poc · Automatable: yes · Technical Impact: totalcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-502USCWE-502USCWE-502US

affected products (5)

Products and version ranges known to be affected.

h2oai h2oai/h2o-3unspecified → 3.46.8enisa_euvdEU
H2O.ai, Inc. H2O≤ 3.46.0.8fstec_bduRU
h2o h2o3.0.0.2 → 3.46.0.8nvdUScpe:2.3:a:h2o:h2o:*:*:*:*:*:*:*:*
Maven ai.h2o:h2o-core≤ 3.46.0.7osvUSpkg:maven/ai.h2o/h2o-core
PyPI h2o≤ 3.46.0.7osvUSpkg:pypi/h2o

advisories (2)

Vendor and ecosystem advisories describing this.

GHSA-5w3j-gwgh-4rfvH2O affected by a deserialization vulnerability2025-09-22ghsa · osvUS
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.
PYSEC-2026-349H2O affected by a deserialization vulnerability2026-06-29vendor · osvUS
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.

also known as (7)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu osv nvd NVD CVE.org MITRE

published 2025-09-21modified 2026-06-17

references (7)

External citations — patches, advisories, analysis.

scry

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