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CVE-2026-0976

Org.keycloak/keycloak-quarkus-server: keycloak: proxy bypass due to improper handling of matrix parameters in url paths

Published: Jan 15, 2026Updated: Aug 9, 2026 Sources: CVE List NVD GHSACWE-20
3.7LOW
NVD MITRE
EPSS Score
0.4%
Top 71.9%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Workaround Only
Self-Check
OpenVAS

Description

A flaw was found in Keycloak. This improper input validation vulnerability occurs because Keycloak accepts RFC-compliant matrix parameters in URL path segments, while common reverse proxy configurations may ignore or mishandle them. A remote attacker can craft requests to mask path segments, potentially bypassing proxy-level path filtering. This could expose administrative or sensitive endpoints that operators believe are not externally reachable.

No summary for this CVE yet.

CVSS Vector Breakdown

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

CWE-20

Affected Products

Red Hat
commercial·US
Red Hat Build of Keycloak
Web & CMS Plugins
Red Hat JBoss Enterprise Application Platform 8On-premWeb App
Enterprise Software / itsm-monitoring
Red Hat JBoss Enterprise Application Platform Expansion PackOn-premOS
Operating Systems / linux-distro
Maven
package-ecosystem
org.keycloak:keycloak-quarkus-server
OSS Libraries

Exploitability

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-2026-0976
access.redhat.com
https://bugzilla.redhat.com/show_bug.cgi?id=2429869
bugzilla.redhat.com
https://nvd.nist.gov/vuln/detail/CVE-2026-0976
nvd.nist.gov
and 1 more references View all →

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