CVEvulnerability
CVE-2026-9803
5.3 MEDIUM
Official page ↗
- Status
- Modified
- Published
- 2026-05-28
- Last modified
- 2026-10-26
- Assigner
- [email protected]
- CVSS 3.1 ([email protected])
- 5.3 MEDIUM — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
- Weaknesses
- CWE-125
Description
A flaw was found in Keycloak's ClientRegistrationAuth component. A remote unauthenticated attacker can exploit this vulnerability by sending a specially crafted POST request with a malformed 'Authorization: Bearer' header to any client registration endpoint. This can lead to an ArrayIndexOutOfBoundsException, causing the server to return an HTTP 500 error and resulting in a Denial of Service (DoS) for the affected service.
Affected configurations
• redhat build of keycloak
Related
Weakness · CWE (1)
- CWE-125 Out-of-bounds Read weakness
References
- https://access.redhat.com/errata/RHSA-2026:25097 access.redhat.com
- https://access.redhat.com/errata/RHSA-2026:25098 access.redhat.com
- https://access.redhat.com/errata/RHSA-2026:30049 access.redhat.com
- https://access.redhat.com/errata/RHSA-2026:30050 access.redhat.com
- https://access.redhat.com/security/cve/CVE-2026-9803 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2482465 Issue Tracking, Vendor Advisory