{"id":"CVE-2026-0976","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-0976","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.","published":"2026-01-15T15:31:17Z","modified":"2026-02-03T03:17:27.858984Z","cvss":{"score":3.7,"severity":"LOW","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Maven","name":"org.keycloak:keycloak-quarkus-server","fixedVersion":null}],"fix":null,"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"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-02-03T03:17:27.858984Z"}}