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 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 victim's credentials. A successful exploit could lead to complete account takeover, including highly privileged administrative accounts.
History

Tue, 19 May 2026 15:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Tue, 19 May 2026 12:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

threat_severity

Important


Tue, 19 May 2026 11:30:00 +0000

Type Values Removed Values Added
Description 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 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 victim's credentials. A successful exploit could lead to complete account takeover, including highly privileged administrative accounts.
Title Org.keycloak/keycloak-services: session fixation in oidc login flow that can lead to account takeover
First Time appeared Redhat
Redhat build Keycloak
Weaknesses CWE-290
CPEs cpe:/a:redhat:build_keycloak:
Vendors & Products Redhat
Redhat build Keycloak
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H'}


cve-icon MITRE

Status: PUBLISHED

Assigner: redhat

Published:

Updated: 2026-05-19T13:40:46.890Z

Reserved: 2026-04-30T14:58:15.177Z

Link: CVE-2026-7507

cve-icon Vulnrichment

Updated: 2026-05-19T13:40:43.278Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-05-19T12:16:19.687

Modified: 2026-05-19T14:25:40.320

Link: CVE-2026-7507

cve-icon Redhat

Severity : Important

Publid Date: 2026-05-19T10:51:31Z

Links: CVE-2026-7507 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-05-19T12:30:05Z