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.
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.001 (2.8th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 3rd percentile — 2.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.001 · newest: 0.001 · change: +0.000
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 (vendor-advisory)
- RHSA-2025:21371 (vendor-advisory)
- RHSA-2025:22088 (vendor-advisory)
- RHSA-2025:22089 (vendor-advisory)
- access.redhat.com/security/cve/CVE-2025-12390 (vdb-entry)
- RHBZ#2406793 (issue-tracking)
- github.com/keycloak/keycloak/issues/43853
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.