CVE-2025-6544 is a critical deserialization vulnerability affecting h2oai/h2o-3 versions up to 3.46.0.8, enabling attackers to read arbitrary system files and execute arbitrary code. This issue stems from improper handling of JDBC connection parameters, which can be exploited via double URL encoding to bypass regular expression checks. With a CVSS score of 9.8 (CRITICAL), it is easily exploitable over the network with no user interaction, leading to complete compromise of confidentiality, integrity, and availability. While there is no known active exploitation, public exploit code, or KEV listing, the vulnerability has garnered some community discussion, indicating awareness among security professionals.
| Vendor | Product | Version(s) | CPE |
|---|---|---|---|
>= 3.0.0.2, <= 3.46.0.8CPE matchmatch criteria | cpe:2.3:a:h2o:h2o:*:*:*:*:*:*:*:* |
CVSS version used by this source: 3.0
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
The average CVE in this peer group has 0.0 Twitter, 0.1 Reddit, 0.3 Bluesky, 0.3 Mastodon, and 2.4 GitHub mentions.
No media coverage found for this CVE.
The average CVE in this peer group has 0.3 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.