Improper Authentication in Keycloak - CVE-2026-19607
Published: September 18, 2026
Vulnerability identifier: #VU150837
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-19607
CWE-ID: CWE-287
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 authentication in the first-broker-login flow of the keycloak-services component when linking an account through an external identity provider. A remote attacker can register a matching username with an external identity provider to cause a denial of service.
Affected software
Keycloak
How to mitigate CVE-2026-19607
Install security update from vendor's website.
Keycloak - update to 26.7.4