Resource exhaustion in Keycloak - #VU146998
Published: September 5, 2026
Vulnerability identifier: #VU146998
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-400
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to improper handling of malformed Authorization headers in ClientRegistrationAuth when processing client registration authentication requests. A remote attacker can send a malformed Authorization header to cause a denial of service.
This issue is an incomplete fix for CVE-2026-0707.
Affected software
Keycloak
Remediation
Install security update from vendor's website.
Keycloak - update to 26.6.3