CVE-2025-12390

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.

Mitigation

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.

Common Vulnerability Scoring System (CVSS) Score Details

Info alert:Important note

CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).

CVSS v3 Score Breakdown

Red HatNVDcve.org
Base Score6N/A6
Attack VectorLocalN/ALocal
Attack ComplexityHighN/AHigh
Privileges RequiredLowN/ALow
User InteractionRequiredN/ARequired
ScopeUnchangedN/AUnchanged
ConfidentialityHighN/AHigh
Integrity ImpactHighN/AHigh
Availability ImpactNoneN/ANone

Vector

Red Hat: CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:N

cve.org: CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:N

Understanding the Weakness (CWE)

Access Control

Technical Impact: Gain Privileges or Assume Identity

Acknowledgements

Red Hat would like to thank Simon Levermann (CTS EVENTIM Solutions GmbH) for reporting this issue.

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