CVE-2026-7571: Red Hat Build Of Keycloak

High severity, CVSS 7.1. EPSS: 0.4% chance of exploitation in the next 30 days.

A flaw was found in Keycloak. A low-privilege user, with knowledge of user credentials and client ID, can bypass a security control intended to disable the implicit flow in OpenID Connect (OIDC) clients. By manipulating client data during a session restart, an attacker can obtain an access token that should not be available. This vulnerability can also lead to the exposure of these access tokens in server logs, proxy logs, and HTTP Referrer headers, resulting in sensitive information disclosure.

Affected products

• Red Hat Build Of Keycloak: from 26.4, before 26.4.12 (fixed in 26.4.12)

Published 2026-05-19. Last modified 2026-06-17.