Authentication Bypass Vulnerability in Keycloak's Client-Initiated Backchannel Authentication
CVE-2026-109082

6.8MEDIUM

Key Information:

Vendor

Red Hat
Status
Red Hat Build Of Keycloak
Red Hat Single Sign-on 7
Vendor
CVE Published:
12 October 2026

What is CVE-2026-109082?

A vulnerability exists in the Client-Initiated Backchannel Authentication (CIBA) implementation of Keycloak, where improper authorization checks allow unauthorized clients to access advanced authentication flows. This flaw allows an attacker to manipulate the login process, potentially tricking users into granting access without the need for a client secret, thereby compromising user accounts.

References

https://access.redhat.com/security/cve/CVE-2026-109082
vdb-entryx_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2549478
issue-trackingx_refsource_REDHAT

CVSS V3.1

Score:
6.8
Severity:
MEDIUM
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
High
Privileges Required:
None
User Interaction:
Required
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Red Hat would like to thank MZOUGHI Mohamed Amine (zerOiQ) for reporting this issue.
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