CVE-2026-18203
Last modified
CVE-2026-18203 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. A flaw was found in the group policy evaluation logic of Keycloak, an identity and access management solution. When a group policy is set to extend permissions to child groups, the system incorrectly uses a simple text-based prefix check to verify group membership. EPSS estimates a 0.20% chance of exploitation in the next 30 days.
Description
A flaw was found in the group policy evaluation logic of Keycloak, an identity and access management solution. When a group policy is set to extend permissions to child groups, the system incorrectly uses a simple text-based prefix check to verify group membership. This allows a user who belongs to a different group with a similar starting name to bypass security checks and gain unauthorized access to administrative functions or protected resources.
Metrics
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Redhat | Build Of Keycloak | All versions |
References
- https://access.redhat.com/security/cve/CVE-2026-18203Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2508291Issue Tracking, Vendor Advisory
Timeline
- Published
- Last Modified
- Status
- Analyzed
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