A flaw was identified in Keycloak, an identity and access management solution, where it improperly follows HTTP redirects when processing certain client configuration requests. This behavior allows an attacker to trick the server into making unintended requests to internal or restricted resources. As a result, sensitive internal services such as cloud metadata endpoints could be accessed. This issue may lead to information disclosure and enable attackers to map internal network infrastructure.
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.


Workaround

To mitigate this vulnerability, restrict the outbound network access of the Keycloak instance. Configure firewall rules to prevent the Keycloak server from initiating connections to internal network segments, especially to well-known cloud metadata service IP addresses such as `169.254.169.254`. For example, on Red Hat Enterprise Linux, you can use `firewalld` to add a rich rule: `sudo firewall-cmd --permanent --zone=public --add-rich-rule='rule family="ipv4" destination address="169.254.169.254" reject'` `sudo firewall-cmd --reload` This may impact other services if they legitimately rely on accessing these internal IPs. Additionally, ensure that any configured `sector_identifier_uri` values are thoroughly validated to only point to trusted, external URLs that do not perform redirects to internal resources.

History

Wed, 18 Mar 2026 18:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Wed, 18 Mar 2026 12:15:00 +0000

Type Values Removed Values Added
First Time appeared Redhat build Of Keycloak
Redhat jboss Enterprise Application Platform Expansion Pack
Vendors & Products Redhat build Of Keycloak
Redhat jboss Enterprise Application Platform Expansion Pack
References
Metrics threat_severity

None

threat_severity

Moderate


Wed, 18 Mar 2026 04:15:00 +0000

Type Values Removed Values Added
Description A flaw was identified in Keycloak, an identity and access management solution, where it improperly follows HTTP redirects when processing certain client configuration requests. This behavior allows an attacker to trick the server into making unintended requests to internal or restricted resources. As a result, sensitive internal services such as cloud metadata endpoints could be accessed. This issue may lead to information disclosure and enable attackers to map internal network infrastructure.
Title Keycloak-services: blind server-side request forgery (ssrf) via http redirect handling in keycloak
First Time appeared Redhat
Redhat build Keycloak
Redhat jboss Enterprise Application Platform
Redhat jbosseapxp
Redhat red Hat Single Sign On
Weaknesses CWE-918
CPEs cpe:/a:redhat:build_keycloak:
cpe:/a:redhat:jboss_enterprise_application_platform:8
cpe:/a:redhat:jbosseapxp
cpe:/a:redhat:red_hat_single_sign_on:7
Vendors & Products Redhat
Redhat build Keycloak
Redhat jboss Enterprise Application Platform
Redhat jbosseapxp
Redhat red Hat Single Sign On
References
Metrics cvssV3_1

{'score': 5.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: redhat

Published:

Updated: 2026-03-18T17:58:48.644Z

Reserved: 2026-03-18T03:43:54.685Z

Link: CVE-2026-4366

cve-icon Vulnrichment

Updated: 2026-03-18T17:53:02.659Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-03-18T04:17:32.450

Modified: 2026-03-18T14:52:44.227

Link: CVE-2026-4366

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-03-18T00:00:00Z

Links: CVE-2026-4366 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-03-18T10:41:50Z

Weaknesses