The URL pattern of "" (the empty string) which exactly maps to the context root was not correctly handled in Apache Tomcat 9.0.0.M1 to 9.0.4, 8.5.0 to 8.5.27, 8.0.0.RC1 to 8.0.49 and 7.0.0 to 7.0.84 when used as part of a security constraint definition. This caused the constraint to be ignored. It was, therefore, possible for unauthorised users to gain access to web application resources that should have been protected. Only security constraints with a URL pattern of the empty string were affected.
Use Apache vendor hub and Tomcat product page to widen CVE-2018-1304 into its surrounding weakness, vendor, and product context.
Compare it with CVE-2026-29145, CVE-2026-34487 and CVE-2026-34486 for nearby disclosures in the same product family.