CVE-2026-97174

A flaw was found in the Client-Initiated Backchannel Authentication (CIBA) implementation of Keycloak. The CIBA endpoint fails to properly validate the sub parameter, allowing it to be stored as an additional request parameter. During the token issuance process, this injected value overwrites the legitimate subject identifier. This allows an attacker to authenticate as themselves but receive security tokens belonging to a different victim user, leading to unauthorized account access.

CVSS v3 6.8 MEDIUM

6.8^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 1.6 / Impact : 5.2

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required LOW

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://access.redhat.com/security/cve/CVE-2026-97174
https://bugzilla.redhat.com/show_bug.cgi?id=2539961

Configurations

No configuration.

History

05 Nov 2026, 18:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-11-05 18:17

Updated : 2026-11-05 21:18

NVD link : CVE-2026-97174

Mitre link : CVE-2026-97174

CVE.ORG link : CVE-2026-97174

JSON object : View

Products Affected

No product.

CWE

CWE-20

Improper Input Validation

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