CVE-2026-4874

Published Mar 26, 2026

Last updated 15 days ago

CVSS low 3.1

Overview

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.
Source
secalert@redhat.com
NVD status
Analyzed
Products
build_of_keycloak, jboss_enterprise_application_platform, jboss_enterprise_application_platform_expansion_pack, single_sign-on

Risk scores

CVSS 3.1

Type
Primary
Base score
3.1
Impact score
1.4
Exploitability score
1.6
Vector string
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N
Severity
LOW

Weaknesses

secalert@redhat.com
CWE-918

Social media

Hype score
Not currently trending

Configurations

Related CVEs

  1. A flaw was found in Undertow. When Undertow receives an HTTP request where the first header line starts with one or more spaces, it incorrectly processes the request by stripping these leading spaces. This behavior, which violates HTTP standards, can be exploited by a remote attacker to perform request smuggling. Request smuggling allows an attacker to bypass security mechanisms, access restricted information, or manipulate web caches, potentially leading to unauthorized actions or data exposure.•CVE-2026-28369
  2. A flaw was found in Undertow. A remote attacker can exploit this vulnerability by sending `\r\r\r` as a header block terminator. This can be used for request smuggling with certain proxy servers, such as older versions of Apache Traffic Server and Google Cloud Classic Application Load Balancer, potentially leading to unauthorized access or manipulation of web requests.•CVE-2026-28367
  3. A flaw was found in Undertow. This vulnerability allows a remote attacker to construct specially crafted requests where header names are parsed differently by Undertow compared to upstream proxies. This discrepancy in header interpretation can be exploited to launch request smuggling attacks, potentially bypassing security controls and accessing unauthorized resources.•CVE-2026-28368
  4. A flaw was found in Keycloak. An administrator with `manage-clients` permission can exploit a misconfiguration where this permission is equivalent to `manage-permissions`. This allows the administrator to escalate privileges and gain control over roles, users, or other administrative functions within the realm. This privilege escalation can occur when admin permissions are enabled at the realm level.•CVE-2026-3121
  5. A flaw was found in Keycloak. The User-Managed Access (UMA) 2.0 Protection API endpoint for permission tickets fails to enforce the `uma_protection` role check. This allows any authenticated user with a token issued for a resource server client, even without the `uma_protection` role, to enumerate all permission tickets in the system. This vulnerability partial leads to information disclosure.•CVE-2026-3190

References

Sources include official advisories and independent security research.