VULNERABILITY INTELLIGENCE

CVE-2026-11800

CVSS score8.1 HIGH
EPSS probability0.30%
CISA KEVNot currently listed
Published2026-06-25
Last modified2026-10-25
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

Description

A flaw was found in Keycloak. This JWT algorithm confusion vulnerability in the JWT Authorization Grant flow allows an attacker with valid client credentials to bypass signature verification. By forging an assertion, the attacker can create unauthorized access tokens. This enables the attacker to impersonate any federated user linked to the affected Identity Provider, leading to unauthorized access and potential privilege escalation.

Weakness classification

  • secalert@redhat.com: CWE-347
  • 0b0ca135-0b70-47e7-9f44-1890c2a1c46c: CWE-347

Primary references