Session Fixation in Keycloak /login-actions restart endpoint (SSO takeover)
CVE-2026-7507 Published on May 19, 2026

Org.keycloak/keycloak-services: session fixation in oidc login flow that can lead to account takeover
A session fixation vulnerability was found in Keycloak's 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 endpointwhich processes session handles without adequate CSRF protection or cookie ownership validationan 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 victim's credentials. A successful exploit could lead to complete account takeover, including highly privileged administrative accounts.

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Vulnerability Analysis

CVE-2026-7507 can be exploited with network access, requires user interaction. This vulnerability is consided to have a high level of attack complexity. The potential impact of an exploit of this vulnerability is considered to be very high.

Attack Vector:
NETWORK
Attack Complexity:
HIGH
Privileges Required:
NONE
User Interaction:
REQUIRED
Scope:
UNCHANGED
Confidentiality Impact:
HIGH
Integrity Impact:
HIGH
Availability Impact:
HIGH

Timeline

Reported to Red Hat.

Made public. 19 days later.

Weakness Type

Authentication Bypass by Spoofing

This attack-focused weakness is caused by improperly implemented authentication schemes that are subject to spoofing attacks.


Products Associated with CVE-2026-7507

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Red Hat Build Keycloak
 
Red Hat Single Sign On
 
Red Hat Rhosemc
 

Affected Versions

Red Hat build of Keycloak 26.2: Red Hat build of Keycloak 26.2: Red Hat build of Keycloak 26.2: Red Hat build of Keycloak 26.2.16: Red Hat build of Keycloak 26.4: Red Hat build of Keycloak 26.4: Red Hat build of Keycloak 26.4: Red Hat build of Keycloak 26.4.12: Red Hat Single Sign-On 7.6.13: Red Hat Single Sign-On 7.6 for RHEL 7: Red Hat Single Sign-On 7.6 for RHEL 8: Red Hat Single Sign-On 7.6 for RHEL 9: Red Hat RHEL-8 based Middleware Containers: Red Hat build of Keycloak 26.2: Red Hat build of Keycloak 26.2: Red Hat build of Keycloak 26.2: Red Hat build of Keycloak 26.2.16: Red Hat build of Keycloak 26.4: Red Hat build of Keycloak 26.4: Red Hat build of Keycloak 26.4: Red Hat build of Keycloak 26.4.12:

Exploit Probability

EPSS
0.41%
Percentile
32.48%

EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.