CVE-2026-0976

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.

Risk Information

Base Score

3.7

MODERATE

Vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N

EPSS Score

Exploitation Probability

0.014

Associated Vulnerability

Vulnerability	OS Platform
Vulnerabilities CVE-2026-0976 are affected in Keycloak--quarkus-server 26.2.5	Windows
Vulnerabilities CVE-2026-0976 are affected in Keycloak--quarkus-server for Linux 26.2.5	Linux

Patch Details

No records found

References

https://nvd.nist.gov/vuln/detail/CVE-2023-1234
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-1234