CVE-2025-6544Disclosure(h2o / h2o)

LOWCVSS 9.8 · CRITICAL

Signal is active with 1 mentions in latest observed window

Immediate actions

Patch h2o h2o systems immediately

Recommended action window: Monitor and triage in normal cycle

NVD 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.

h2o CVEs Back to dashboard

0.5/ 10 priority

Sources & remediation

Patch / fix

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

Exploit / PoC references

Weakness type (CWE)

CWE-502

Priority

LOW

Exploitation

NONE

PoC

YES

Patch

AVAILABLE

Momentum

NONE

Are you affected?

If you run products in this scope, you should treat this CVE as relevant to your environment.

Threat summary

Patch or workaround signal is available
1 mentions across 1 observed day

What's happening

Patch or workaround mentioned in 1 signal
Technical details provided in 1 signal
Disclosure: 1 classified signal
1 total mentions across 1 day

Affected systems

Vendors

h2o

Products

h2o

Deep dive

Activity timeline1 mentions / 1d

Signal classification1 categories

Disclosure

1100.0%

Referenced assets1 URL

By indicator

https://www.valtersit.com/cve/CVE-2025-6544/

Full discourse1 post

Hugo | DevOps | Cybersecurity 🇱🇻@HugoValters139d
Disclosure
CVE-2025-6544 - Critical insecure deserialization in H2oai h2o-3 <=3.46.0.8. Arbitrary file read & RCE via JDBC parameter bypass. CVSS 9.8. No patch available - mitigate immediately. #CVE #InfoSec #Cybersecurity #infosecurity #100daysofcode #python more: https://www.valtersit.com/cve/CVE-2025-6544/
Post summary
A critical insecure deserialization flaw (CVE‑2025‑6544) in H2oai h2o‑3 (<=3.46.0.8) permits arbitrary file read and RCE via JDBC parameter bypass, rated CVSS 9.8; no patch exists yet, so immediate mitigation is advised.
00000765
904 followersView on X

CPE platform detail1 entries

Part:

Vendor:

Product:

Version:

Target SW:

Target HW:

1 of 1 entries

Part	Vendor	Product	Version	Target SW	Target HW
App	h2o	h2o	-	-	-

Explore more

Back to dashboard h2o CVEs h2o vulnerabilities