Medium (6.5). EPSS 0.9% chance of exploitation in the next 30 days. Fixed in org.keycloak:keycloak-quarkus-server 26.0.8.
A denial of service vulnerability was found in Keycloak that could allow an administrative user with the right to change realm settings to disrupt the service. This action is done by modifying any of the security headers and inserting newlines, which causes the Keycloak server to write to a request that has already been terminated, leading to the failure of said request.
Severity
CVSS 3.1
6.5 medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS
0.9% chance of exploitation in the next 30 days; higher than 61% of CVEs (scores of 2026-10-31)