CVE-2025-12390

Org.keycloak.protocol.oidc.endpoints.logoutendpoint: offline session takeover due to reused authentication session id

Published Oct 28, 2025 CVSS 3.1 · 6 Medium EPSS < 1% KEV · Not listed
Description
A flaw was found in Keycloak. In Keycloak where a user can accidentally get access to another user's session if both use the same device and browser. This happens because Keycloak sometimes reuses session identifiers and doesn’t clean up properly during logout when browser cookies are missing. As a result, one user may receive tokens that belong to another user.

Remediation

Vendor Workaround

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-rg35-5v25-mqvp Keycloak vulnerable to session takeovers due to reuse of session identifiers
History
Type Values Removed Values Added
CPEs cpe:/a:redhat:build_keycloak: cpe:/a:redhat:build_keycloak:26.4::el9
References
Type Values Removed Values Added
Metrics ssvc

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

Type Values Removed Values Added
Description A flaw was found in Keycloak. In Keycloak where a user can accidentally get access to another user's session if both use the same device and browser. This happens because Keycloak sometimes reuses session identifiers and doesn’t clean up properly during logout when browser cookies are missing. As a result, one user may receive tokens that belong to another user.
Title Org.keycloak.protocol.oidc.endpoints.logoutendpoint: offline session takeover due to reused authentication session id
First Time appeared Redhat
Redhat build Keycloak
Weaknesses CWE-384
CPEs cpe:/a:redhat:build_keycloak:
Vendors & Products Redhat
Redhat build Keycloak
References
Metrics cvssV3_1

{'score': 6, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
redhat
Published
Updated
Jul 30, 2026, 9:41 AM
Reserved
Oct 28, 2025, 1:14 PM
Status
Deferred
Published
Oct 28, 2025, 2:15 PM
Modified
Oct 18, 2026, 9:10 PM
Severity
Moderate
Public date
Oct 28, 2025, 12:00 AM