CVE-2026-9793 MEDIUM

CVE-2026-9793: Keycloak: keycloak: security policy bypass in jwe-encrypted request object processing

Vendor Red Hat
Product Red Hat Build of Keycloak
Weakness CWE-347
Published May 28, 2026
Last update May 30, 2026

CVSS base score

5.9/10
Attack vector Network
Attack complexity High
Privileges required None
User interaction None
Confidentiality None
Integrity High

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N

What the vulnerability does

01Description

A flaw was found in Keycloak. When a JSON Web Encryption (JWE) encrypted request object is submitted, Keycloak may incorrectly process unsigned claims if the decrypted content is raw JSON, bypassing the configured signature policy. This allows a remote attacker to submit unauthorized claims, leading to a compromise of data integrity within the OpenID Connect (OIDC) authorization flow. While a redirect URI allowlist acts as a compensating control, this vulnerability violates OIDC Core and Financial-grade API (FAPI) signing requirements.

Key dates

02Disclosure timeline

May 28, 2026 CVE published
May 30, 2026 Record updated