CVE-2026-4366

Name: CVE-2026-4366
Creator: NVD / NIST
Published: 2026-03-18T04:17:32.45+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.8/10EPSS 0.23%

Last modified Jun 17, 2026

CVE-2026-4366 is a medium-severity vulnerability rated 5.8/10 on the CVSS scale. 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. EPSS estimates a 0.23% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

5.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N

EPSS Probability

0.23%

13.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-918

Affected Software

Vendor	Product	Versions
Redhat	Build Of Keycloak	All versions
Redhat	Jboss Enterprise Application Platform	8.0.0
Redhat	Jboss Enterprise Application Platform Expansion Pack	All versions
Redhat	Single Sign-On	7.0

References

https://access.redhat.com/errata/RHSA-2026:19596
https://access.redhat.com/errata/RHSA-2026:19597
https://access.redhat.com/security/cve/CVE-2026-4366Vendor Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2448543Issue Tracking, Vendor Advisory

Timeline

Published: Mar 18, 2026
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2026-4366?

How severe is CVE-2026-4366?

CVE-2026-4366 has a CVSS score of 5.8/10 (MEDIUM severity). The EPSS model estimates a 0.23% probability of exploitation in the next 30 days.

How do I fix CVE-2026-4366?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-4366?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST