{"cve":"CVE-2026-0976","nvd":{"published":"2026-01-15T13:16:04.910","modified":"2026-10-22T22:17:41.857","status":"Deferred","description":"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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N","score":3.7},"cwes":["CWE-20"],"references":["https://access.redhat.com/errata/RHSA-2026:2365","https://access.redhat.com/security/cve/CVE-2026-0976","https://bugzilla.redhat.com/show_bug.cgi?id=2429869"],"products":[],"source":"nvd","synced_at":"2026-10-23T16:39:26.291718493+00:00"},"epss":{"cve":"CVE-2026-0976","score":0.00489,"percentile":0.41806,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-v897-pv23-r8cw","url":"https://osv.dev/vulnerability/GHSA-v897-pv23-r8cw","summary":"Keycloak has an improper input validation vulnerability","modified":"2026-10-23T00:45:08.188819869Z","packages":[{"ecosystem":"Maven","name":"org.keycloak:keycloak-quarkus-server","purl":"pkg:maven/org.keycloak/keycloak-quarkus-server","ranges":["<=26.2.5"],"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."]}