VULNERABILITY INTELLIGENCE

CVE-2026-9803

CVSS score5.3 MEDIUM
EPSS probability0.42%
CISA KEVNot currently listed
Published2026-05-28
Last modified2026-10-26
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

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.

Weakness classification

  • secalert@redhat.com: CWE-125

Primary references