CVE-2025-12390 | Org.keycloak.protocol.oidc.endpoints.logoutendpoint: offline session takeover due to reused authentication session id

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: 2025-10-28 Last update: 2026-04-15 Assigner: [email protected] Source: [email protected]
NVD Status：Deferred，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2025-12390 is rated Low Risk (24.4/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.01%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-12390

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-10-29 — 0.01% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-12390

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.0 3.1 MEDIUM
CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:N Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
 0.8 5.2 [email protected]

Weakness enumeration for CVE-2025-12390

GitHub Security Advisory for CVE-2025-12390

GHSA-rg35-5v25-mqvp · Severity: medium · Ecosystem: maven — Keycloak vulnerable to session takeovers due to reuse of session identifiers

OS Trackers for CVE-2025-12390

vendor priority summary link
redhat medium — https://access.redhat.com/security/cve/CVE-2025-12390

Affected software / configurations for CVE-2025-12390

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2025-12390

cvelogic Threat Intelligence