CVE-2026-0976

State: PUBLISHED · Published: 2026-01-15 · Updated: 2026-01-15 · Assigner: redhat

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.

CWE

CWE-20 — Improper Input Validation

Affected

Red Hat / Red Hat Build of Keycloak —
Red Hat / Red Hat JBoss Enterprise Application Platform 8 —
Red Hat / Red Hat JBoss Enterprise Application Platform 8 —
Red Hat / Red Hat JBoss Enterprise Application Platform 8 —
Red Hat / Red Hat JBoss Enterprise Application Platform Expansion Pack —
Red Hat / Red Hat JBoss Enterprise Application Platform Expansion Pack —
Red Hat / Red Hat JBoss Enterprise Application Platform Expansion Pack —

CVSS

3.1 score=3.7 severity=LOW CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N

References

https://access.redhat.com/security/cve/CVE-2026-0976 vdb-entry, x_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2429869 issue-tracking, x_refsource_REDHAT

Source

cvelistV5-main/cves/2026/0xxx/CVE-2026-0976.json