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CVE-2026-18211

Keycloak-services: keycloak-services: secure-client-uris policy bypass via localhost-prefixed domains

Published: Jul 31, 2026Updated: Aug 7, 2026 Sources: CVE List NVDCWE-20
4.2MEDIUM
NVD MITRE
EPSS Score
0.2%
Top 92.5%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available
Self-Check
OpenVAS

Description

A flaw was found in the secure-client-uris client policy executor within Keycloak core services. This component is responsible for enforcing security requirements on client configurations, such as requiring encrypted connections for redirect URIs. Due to an improper check that only looks at the start of a web address rather than properly verifying the host, an attacker can bypass these security restrictions by using a specially crafted domain name. This could allow an attacker to intercept sensitive authentication codes over unencrypted connections.

No summary for this CVE yet.

CVSS Vector Breakdown

AV:NAC:HPR:NUI:RS:UC:LI:LA:N
Exploitability
AV:NAttack Vector
Network
AC:HAttack Complexity
High
PR:NPrivileges Required
None
UI:RUser Interaction
Required
Scope
S:UScope
Unchanged
Impact
C:LConfidentiality
Low
I:LIntegrity
Low
A:NAvailability
None
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Weaknesses

CWE-20

Affected Products

Red Hat
commercial·USaka redhat
build of keycloakOn-prem
Operating Systems / linux-distro
Red Hat Build of Keycloak
Web & CMS Plugins
Red Hat Data Grid 8On-premDatabase
Databases / cache-message-queue
Red Hat JBoss Enterprise Application Platform Expansion PackOn-premOS
Operating Systems / linux-distro
Red Hat Single Sign-On 7On-premSecurity Product
Security Products / identity-access-mgmt

Exploitability

Official Patch Available
Workaround Available
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Attack Graph

Products CVE Techniques Tactics

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MITRE ATT&CK

1 technique
Initial Access
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References

https://access.redhat.com/security/cve/CVE-2026-18211
access.redhat.com
https://bugzilla.redhat.com/show_bug.cgi?id=2508306
bugzilla.redhat.com

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