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Fencer Intel
medium 6.0

CVE-2025-12390 json

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

published last yr. modified 24d ago also GHSA-rg35-5v25-mqvp , EUVD-2025-36502

cvss
6.0
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.1%
EPSS 0.1% chance of exploitation in 30 days, percentile 3%
public exploits
0
none known

Summary

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.

Patch / fix

  • maven org.keycloak:keycloak-services 26.0.0
  • Keycloak keycloak 26.0.0
  • Red Hat Red Hat build of Keycloak 26.2 26.2-12, 26.2.11-1
  • Red Hat Red Hat build of Keycloak 26.4 26.4-3, 26.4.4-1

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2025-12390 updated cvss 6.0

org.keycloak.protocol.oidc.endpoints.LogoutEndpoint: Offline Session takeover due to reused Authentication Session ID

  • Red Hat build of Keycloak 26.2 rhbk/keycloak-rhel9 26.2-12, rhbk/keycloak-rhel9-operator 26.2-12, rhbk/keycloak-operator-bundle 26.2.11-1
    fixed: vendor fix RHSA-2025:22088
  • Red Hat build of Keycloak 26.2.11
    fixed: vendor fix RHSA-2025:22089
  • Red Hat build of Keycloak 26.4 rhbk/keycloak-rhel9 26.4-3, rhbk/keycloak-rhel9-operator 26.4-3, rhbk/keycloak-operator-bundle 26.4.4-1
    fixed: vendor fix RHSA-2025:21371
  • Red Hat build of Keycloak 26.4.4
    fixed: vendor fix RHSA-2025:21370

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
last yr.

Exploit prediction

0.14% chance of exploitation in the next 30 days, higher than 3% of all scored CVEs (FIRST EPSS, 2026-11-11).

CVSS scores

assigned by version score vector
CNA 3.1 6.0 CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:N
GitHub 3.1 6.0 CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:N

Affected packages

ecosystem package affected fixed in
maven org.keycloak:keycloak-services
<26.0.0
26.0.0

Affected products

  • Keycloak keycloak
  • Red Hat Red Hat build of Keycloak 26.2
  • Red Hat Red Hat build of Keycloak 26.2.11
  • Red Hat Red Hat build of Keycloak 26.4
  • Red Hat Red Hat build of Keycloak 26.4.4

Classification

Weakness

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.