CVE-2025-12390Hinoki check available

Session takeover via retained authentication session identifier

Published Oct 28, 2025 · Updated Oct 28, 2025

Session fixation in Red Hat build of Keycloak allows local users sharing a browser to receive another user's session tokens. The OIDC LogoutEndpoint processes an id_token_hint without a session cookie by deleting the user session but leaving its authentication session alive for 60 seconds under the same identifier. A subsequent login from the same device and browser can reuse that identifier and obtain the previous user's tokens; this requires an authenticated user and user interaction.

CVSS severity6.0
Medium
EPSS probability0.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Session fixation in Red Hat build of Keycloak allows local users sharing a browser to receive another user's session tokens. The OIDC LogoutEndpoint processes an id_token_hint without a session cookie by deleting the user session but leaving its authentication session alive for 60 seconds under the same identifier. A subsequent login from the same device and browser can reuse that identifier and obtain the previous user's tokens; this requires an authenticated user and user interaction.

The record

CVE
CVE-2025-12390
Published
Oct 28, 2025
Updated
Oct 28, 2025
Vendor
389 Directory Server
Product
Red Hat build of Keycloak
Classifications
CWE-384, CAPEC-61, T1539
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 28, 2025CVE publishedPublication date reported by the CVE source.
  2. Oct 28, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

389 Directory Server · Red Hat build of KeycloakAffected versions are unavailable in this record.

Published CVSS scores

6.0Red HatCVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-384Session Fixation
CAPEC-61Session Fixation
T1539Steal Web Session Cookie

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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