{"cve":"CVE-2025-6544","nvd":{"published":"2025-09-21T09:15:38.497","modified":"2026-10-05T14:10:00.267","status":"Analyzed","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.","cvss_v4":null,"cvss_v3":{"version":"3.0","vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","score":9.8},"cwes":["CWE-502"],"references":["https://github.com/h2oai/h2o-3/commit/0298ee348f5c73673b7b542158081e79605f5f25","https://huntr.com/bounties/53f35a0f-d644-4f82-93aa-89fe7e0aed40","https://huntr.com/bounties/53f35a0f-d644-4f82-93aa-89fe7e0aed40"],"products":["h2o:h2o"],"source":"nvd","synced_at":"2026-10-19T22:10:08.713834912+00:00"},"epss":{"cve":"CVE-2025-6544","score":0.00919,"percentile":0.59992,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-5w3j-gwgh-4rfv","url":"https://osv.dev/vulnerability/GHSA-5w3j-gwgh-4rfv","summary":"H2O affected by a deserialization vulnerability","modified":"2026-06-29T12:26:32.691823215Z","packages":[{"ecosystem":"Maven","name":"ai.h2o:h2o-core","purl":"pkg:maven/ai.h2o/h2o-core","ranges":["<=3.46.0.7"],"fixed":[]},{"ecosystem":"PyPI","name":"h2o","purl":"pkg:pypi/h2o","ranges":["<=3.46.0.7"],"fixed":[]}]},{"id":"PYSEC-2026-349","url":"https://osv.dev/vulnerability/PYSEC-2026-349","summary":"H2O affected by a deserialization vulnerability","modified":"2026-07-01T20:22:54.093490Z","packages":[{"ecosystem":"PyPI","name":"h2o","purl":"pkg:pypi/h2o","ranges":["<=3.46.0.7"],"fixed":[]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}