A session fixation vulnerability was found in Keycloaks login-actions endpoints. An unauthenticated attacker could exploit this flaw by pre-creating an authentication session and tricking a victim into visiting a maliciously crafted link. By leveraging the /login-actions/restart endpoint—which processes session handles without adequate CSRF protection or cookie ownership validation—an attacker can reset the authentication flow state. This causes Single Sign-On (SSO) to authenticate the victim transparently upon clicking the link, allowing the attacker to hijack the required-action form without needing the victims credentials. A successful exploit could lead to complete account takeover, including highly privileged administrative accounts.
This attack-focused weakness is caused by incorrectly implemented authentication schemes that are subject to spoofing attacks.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Build_of_keycloak | Redhat | 26.4 (including) | 26.4.12 (excluding) |
| Red Hat build of Keycloak 26.2 | RedHat | rhbk/keycloak-operator-bundle:26.2.16-1 | * |
| Red Hat build of Keycloak 26.2 | RedHat | rhbk/keycloak-rhel9:26.2-21 | * |
| Red Hat build of Keycloak 26.2 | RedHat | rhbk/keycloak-rhel9-operator:26.2-21 | * |
| Red Hat build of Keycloak 26.2.16 | RedHat | rhbk/keycloak-rhel9-operator | * |
| Red Hat build of Keycloak 26.4 | RedHat | rhbk/keycloak-operator-bundle:26.4.12-1 | * |
| Red Hat build of Keycloak 26.4 | RedHat | rhbk/keycloak-rhel9:26.4-17 | * |
| Red Hat build of Keycloak 26.4 | RedHat | rhbk/keycloak-rhel9-operator:26.4-17 | * |
| Red Hat build of Keycloak 26.4.12 | RedHat | rhbk/keycloak-rhel9-operator | * |