CVE-2026-4874

medium

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.

References

https://bugzilla.redhat.com/show_bug.cgi?id=2451611

https://access.redhat.com/security/cve/CVE-2026-4874

Details

Source: Mitre, NVD

Published: 2026-03-26

Updated: 2026-03-26

Risk Information

CVSS v2

Base Score: 2.1

Vector: CVSS2#AV:N/AC:H/Au:S/C:P/I:N/A:N

Severity: Low

CVSS v3

Base Score: 6.5

Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Severity: Medium