Bug 2448543 (CVE-2026-4366)

Summary:	CVE-2026-4366 keycloak-services: Blind Server-Side Request Forgery (SSRF) via HTTP Redirect Handling in Keycloak
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security <prodsec-ir-bot>
Status:	CLOSED ERRATA	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	abhraj, aschwart, asoldano, bbaranow, bmaxwell, boliveir, bstansbe, dlofthou, istudens, ivassile, iweiss, mosmerov, mposolda, msvehla, nwallace, pberan, pesilva, pjindal, pmackay, rmartinc, rstancel, smaestri, ssilvert, sthorger, thjenkin, vdosoudi, vmuzikar
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	---
Doc Text:	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.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2026-06-15 08:16:23 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-03-18 03:47:33 UTC

Server-Side Request Forgery (SSRF) vulnerability in Keycloak due to improper handling of HTTP redirects during client configuration processing. The flaw arises because Keycloak follows redirect responses (e.g., HTTP 302) without validating the final destination URL. An attacker can supply a crafted sector_identifier_uri that initially matches allowed patterns but redirects to internal resources such as cloud metadata endpoints (e.g., 169.254.169.254). This causes Keycloak to issue unintended requests from its network context, enabling blind SSRF. The vulnerability can be exploited remotely without authentication or user interaction, allowing attackers to perform internal network reconnaissance and potentially access sensitive information.