{"id":"GHSA-v897-pv23-r8cw","summary":"Keycloak has an improper input validation vulnerability","details":"A flaw was found in Keycloak. This improper input validation vulnerability occurs because Keycloak accepts RFC-compliant matrix parameters in URL path segments, while common reverse proxy configurations may ignore or mishandle them. A remote attacker can craft requests to mask path segments, potentially bypassing proxy-level path filtering. This could expose administrative or sensitive endpoints that operators believe are not externally reachable.","aliases":["CVE-2026-0976"],"modified":"2026-02-03T03:17:27.858984Z","published":"2026-01-15T15:31:17Z","database_specific":{"cwe_ids":["CWE-20"],"severity":"LOW","github_reviewed":true,"github_reviewed_at":"2026-01-15T23:10:39Z","nvd_published_at":"2026-01-15T13:16:04Z"},"references":[{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-0976"},{"type":"WEB","url":"https://access.redhat.com/security/cve/CVE-2026-0976"},{"type":"WEB","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2429869"},{"type":"PACKAGE","url":"https://github.com/keycloak/keycloak"}],"affected":[{"package":{"name":"org.keycloak:keycloak-quarkus-server","ecosystem":"Maven","purl":"pkg:maven/org.keycloak/keycloak-quarkus-server"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"26.2.5"}]}],"versions":["12.0.0","12.0.1","12.0.2","12.0.3","12.0.4","13.0.0","13.0.1","14.0.0","15.0.0","15.0.1","15.0.2","15.1.0","15.1.1","16.0.0","16.1.0","16.1.1","17.0.0","17.0.1","18.0.0","18.0.1","18.0.2","19.0.0","19.0.1","19.0.2","19.0.3","20.0.0","20.0.1","20.0.2","20.0.3","20.0.4","20.0.5","21.0.0","21.0.1","21.0.2","21.1.0","21.1.1","21.1.2","22.0.0","22.0.1","22.0.2","22.0.3","22.0.4","22.0.5","23.0.0","23.0.1","23.0.2","23.0.3","23.0.4","23.0.5","23.0.6","23.0.7","24.0.0","24.0.1","24.0.2","24.0.3","24.0.4","24.0.5","25.0.0","25.0.1","25.0.2","25.0.3","25.0.4","25.0.5","25.0.6","26.0.0","26.0.1","26.0.2","26.0.4","26.0.5","26.0.6","26.0.7","26.0.8","26.1.0","26.1.1","26.1.2","26.1.3","26.1.4","26.1.5","26.2.0","26.2.1","26.2.2","26.2.3","26.2.4","26.2.5"],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/01/GHSA-v897-pv23-r8cw/GHSA-v897-pv23-r8cw.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N"}]}