Bug 2499593 (CVE-2026-15573)

Summary:	CVE-2026-15573 keycloak-services: keycloak-services: Authorization bypass via unnormalized URI matching in PathMatcher
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security <prodsec-ir-bot>
Status:	NEW ---	QA Contact:
Severity:	high	Docs Contact:
Priority:	high
Version:	unspecified	CC:	anujha, aschwart, asoldano, aszczucz, bbaranow, bmaxwell, boliveir, bstansbe, dlofthou, drichtar, istudens, ivassile, iweiss, mosmerov, mposolda, msvehla, nwallace, pberan, pesilva, pjindal, pmackay, rmartinc, rstancel, security-response-team, 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 found in Keycloak's Authorization Services. The component responsible for matching request paths to security policies (PathMatcher) does not properly normalize URIs before comparison. By adding extra characters like a trailing slash or matrix parameters to a URL, an attacker can trick the system into applying a less restrictive security policy than intended. This allows an authenticated user to access administrative or restricted areas they should not have permission to see.	Story Points:	---
Clone Of:		Environment:
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Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Deadline:	2026-10-04

Description OSIDB Bzimport 2026-07-13 07:38:12 UTC

Keycloak Authorization Services resolves request URIs to protected Resources using PathMatcher (org.keycloak.common.util.PathMatcher), which performs purely lexical segment comparison with no URI normalization. Appending a matrix parameter (;x=1) or trailing / to a restricted resource URI causes it to miss the exact match and fall through to a broader, more permissive resource (e.g., the default /* catch-all).
An authenticated low-privilege user can obtain a granted RPT or positive authorization decision for resources the policy explicitly denies them. The vulnerability affects the UMA grant endpoint, the Protection API matchingUri resolution, and the client-side policy enforcer—all of which share the same unguarded PathMatcher.