CVE-2026-4874

LOW3.1EPSS 0.01%

Keycloak Server-Side Request Forgery via OIDC token endpoint manipulation

Published: 3/26/2026Modified: 4/13/2026

Description

A flaw was found in Keycloak. An authenticated attacker can perform Server-Side Request Forgery (SSRF) by manipulating the `client_session_host` parameter during refresh token requests. This occurs when a Keycloak client is configured to use the `backchannel.logout.url` with the `application.session.host` placeholder. Successful exploitation allows the attacker to make HTTP requests from the Keycloak server’s network context, potentially probing internal networks or internal APIs, leading to information disclosure.

Affected packages (1)

CVSS scores

SourceVersionSeverityVector
osvCVSS 3.1LOW3.1CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N

References (4)