What’s Vulnerable › Vulnerabilities

CVE-2026-105306: Keycloak-services: keycloak-services: token introspection audience bypass via dynamic client registration

• Severity: medium (CVSS 6.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-05 · updated 2026-10-06
• Weakness: CWE-862

Description

A flaw was found in the Dynamic Client Registration flow of the Keycloak identity and access management server. The issue occurs because the registration process fails to filter security-sensitive client attributes when a new client is created. An attacker with a valid Initial Access Token can register a client that bypasses audience checks during token introspection. This allows the attacker to view sensitive identity information, roles, and session details from access tokens belonging to other applications in the same realm.

Affected products

• Red Hat build of Keycloak 26.4: all versions

References

• https://access.redhat.com/security/cve/CVE-2026-105306
• https://bugzilla.redhat.com/show_bug.cgi?id=2545802

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