Keycloak-services: keycloak-services: broker-originated username collision causes account lockout
13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 5.3epss 0.5%
exploitation probability
0.5%top 58% of all CVEs
observed exploitation
nono source reports it
A flaw was found in the first-broker-login flow of the keycloak-services component. This component handles the initial authentication and account linking when a user logs in via an external identity provider. The issue allows an attacker to register a matching username on an external provider to trigger a collision in Keycloak, which results in the legitimate user being locked out of their account.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Affected products
Red Hat · Red Hat build of Keycloak 26.4Red Hat · Red Hat build of Keycloak 26.4.16Red Hat · Red Hat build of Keycloak 26.6Red Hat · Red Hat build of Keycloak 26.6.7Red Hat · Red Hat Single Sign-On 7References
https://access.redhat.com/errata/RHSA-2026:68276https://access.redhat.com/errata/RHSA-2026:68277https://access.redhat.com/errata/RHSA-2026:68278https://access.redhat.com/errata/RHSA-2026:68280https://access.redhat.com/security/cve/CVE-2026-19607https://bugzilla.redhat.com/show_bug.cgi?id=2514529