CVE-2026-0976
Org.keycloak/keycloak-quarkus-server: keycloak: proxy bypass due to improper handling of matrix parameters in url paths
- State
- Published
- Severity
- 3.7 Low
- Published
- Jan 15, 2026
- Updated
- Oct 22, 2026
- Reserved
- Jan 15, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 3.7 Low | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N | redhat |
Weaknesses
- CWE-20 Improper Input Validation
Affected Products
| Product | Versions |
|---|---|
Red Hat build of Keycloak 26.4.9Red Hat | |
Red Hat Build of KeycloakRed Hat | |
Red Hat JBoss Enterprise Application Platform 8Red Hat | |
Red Hat JBoss Enterprise Application Platform 8Red Hat | |
Red Hat JBoss Enterprise Application Platform 8Red Hat | |
Red Hat JBoss Enterprise Application Platform Expansion PackRed Hat | |
Red Hat JBoss Enterprise Application Platform Expansion PackRed Hat | |
Red Hat JBoss Enterprise Application Platform Expansion PackRed Hat |
References
- RHSA-2026:2365vendor-advisory
- https://access.redhat.com/security/cve/CVE-2026-0976vdb-entry
- RHBZ#2429869issue-tracking
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