CVE-2026-0976

LOW

Keycloak - Path Filter Bypass via RFC-Compliant Matrix Parameters

Title source: llm
STIX 2.1

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.

References (2)

Core 2
Core References
Vendor Advisory vdb-entry x_refsource_redhat
https://access.redhat.com/security/cve/CVE-2026-0976
Issue Tracking issue-tracking x_refsource_redhat
https://bugzilla.redhat.com/show_bug.cgi?id=2429869

Scores

CVSS v3 3.7
EPSS 0.0001
EPSS Percentile 3.5%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

CWE
CWE-20
Status published
Products (4)
org.keycloak/keycloak-quarkus-server 0Maven
Red Hat/Red Hat Build of Keycloak
Red Hat/Red Hat JBoss Enterprise Application Platform 8
Red Hat/Red Hat JBoss Enterprise Application Platform Expansion Pack
Published Jan 15, 2026
Tracked Since Feb 18, 2026