CVE-2026-97174
Keycloak-services: keycloak-services: ciba sub parameter injection causes attacker authentication to issue victim tokens
CVSS Score
6.8
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-20 |
| Vendor | red hat |
| Product | red hat build of keycloak |
| Published | Nov 5, 2026 |
| Last Updated | Nov 5, 2026 |
Stay Ahead of the Next One
Get instant alerts for red hat red hat build of keycloak
Be the first to know when new medium vulnerabilities affecting red hat red hat build of keycloak are published — delivered to Slack, Telegram or Discord.
Get Free Alerts →
Free · No credit card · 60 sec setup
CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N Attack Vector
Network
Attack Complexity
High
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None
Affected Versions
Red Hat / Red Hat Build of Keycloak
All versions affected Red Hat / Red Hat Build of Keycloak
All versions affected Red Hat / Red Hat Single Sign-On 7
All versions affected References
Credits
Red Hat would like to thank Amr Al Hallak (v4yne1) for reporting this issue.