{"id":"CVE-2025-6544","url":"https://www.cyber-defence.io/tools/cve/CVE-2025-6544","generatedAt":"2026-10-28T00:18:10.842Z","title":"A deserialization vulnerability exists in h2oai/h2o-3 versions <= 3.46.0.8, allowing attackers to read arbitrary system files and execute arbitrary code.","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.","published":"2025-09-21T09:15:38.000Z","lastModified":"2026-10-05T14:10:00.000Z","status":"Analyzed","sourceIdentifier":"security@huntr.dev","cvss":{"version":"3.0","score":9.8,"severity":"CRITICAL","vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"},"cwe":["CWE-502"],"affected":["h2o/h2o"],"epss":{"score":0.00919,"percentile":0.5999,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.92%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://github.com/h2oai/h2o-3/commit/0298ee348f5c73673b7b542158081e79605f5f25","tags":["Patch"],"source":"security@huntr.dev"},{"url":"https://huntr.com/bounties/53f35a0f-d644-4f82-93aa-89fe7e0aed40","tags":["Exploit","Third Party Advisory"],"source":"security@huntr.dev"},{"url":"https://huntr.com/bounties/53f35a0f-d644-4f82-93aa-89fe7e0aed40","tags":["Exploit","Third Party Advisory"],"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2025-6544","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}