PT-2026-44196 · Red Hat · Red Hat Build Of Keycloak

Published 2026-05-28 · Updated 2026-05-28 · CVE-2026-9803

Mitre

CVSS v3.1

5.3

Medium

Base vector

AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

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.

Fix

Out of bounds Read

Weakness Enumeration

CWE-125

Related Identifiers

CVE-2026-9803

Affected Products

Red Hat Build Of Keycloak

References · 3

• https://nvd.nist.gov/vuln/detail/CVE-2026-9803 · Security Note
• https://access.redhat.com/security/cve/CVE-2026-9803 · Note
• https://bugzilla.redhat.com/show_bug.cgi?id=2482465 · Note