Auth bypass in Red Hat Build Of Keycloak

CVE-2026-74909

Keycloak provides a policy enforcer to protect applications by matching incoming web requests against defined security policies. A flaw was found where the enforcer fails to correctly normalize web addresses that contain special encoded characters, such as those representing semicolons or directory traversal segments. An authenticated user can use these encoded characters to trick the enforcer into applying a less restrictive security policy than intended, potentially gaining unauthorized access to sensitive administrative or private application endpoints.

Vulnerability class: Broken Access Control

CVSS v3 metric

CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-74909?
CVE-2026-74909 is a high-severity vulnerability in Red Hat Build Of Keycloak, classified under Missing Authorization. CVSS score: 8.1/10. Published 2026-09-16.
How severe is CVE-2026-74909?
High severity. CVSS v3 base score is 8.1 out of 10.