Vulnerability in Keycloak
CVE-2025-12390
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.
EPSS: 0.001 (3.0th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.0 (Medium). Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:N.
Affected products
- Keycloak — versions 0
- Red Hat Build Of Keycloak 26.2 — versions 26.2.11-1, 26.2-12
- Red Hat Build Of Keycloak 26.2.11
- Red Hat Build Of Keycloak 26.4 — versions 26.4.4-1, 26.4-3
- Red Hat Build Of Keycloak 26.4.4
Weakness classification (CWE)
References
- RHSA-2025:21370 (x_refsource_REDHAT, vendor-advisory)
- RHSA-2025:21371 (x_refsource_REDHAT, vendor-advisory)
- RHSA-2025:22088 (x_refsource_REDHAT, vendor-advisory)
- RHSA-2025:22089 (x_refsource_REDHAT, vendor-advisory)
- secalert@redhat.com (x_refsource_REDHAT, vdb-entry)
- RHBZ#2406793 (x_refsource_REDHAT, issue-tracking)
- secalert@redhat.com
Frequently asked questions
- What is CVE-2025-12390?
- CVE-2025-12390 is a medium-severity vulnerability in Keycloak, classified under Session Fixation. CVSS score: 6.0/10. Published 2025-10-28.
- How severe is CVE-2025-12390?
- Medium severity. CVSS v3 base score is 6.0 out of 10.