CVE-2026-50559: Quarkus

High severity, CVSS 7.5. EPSS: 1% chance of exploitation in the next 30 days.

Quarkus is a Java framework for building cloud-native applications. Prior to versions 3.37.0, 3.36.3, 3.33.2.1, 3.33.3, 3.27.4.1, 3.27.5, and 3.20.6.2, Quarkus HTTP path-based authorization policies can be bypassed using encoded semicolons (%3B) to smuggle matrix parameters past the security layer, and using encoded slashes (%2F) or backslashes (%5C) to access protected static resources. This is a distinct issue from CVE-2026-39852, which addressed only literal semicolon stripping. Versions 3.37.0, 3.36.3, 3.33.2.1, 3.33.3, 3.27.4.1, 3.27.5, and 3.20.6.2 contain a patch.

Affected products

• Quarkus Quarkus: before 3.20.6.2 (fixed in 3.20.6.2); from 3.21.0, before 3.27.4.1 (fixed in 3.27.4.1); from 3.28.0, before 3.33.2.1 (fixed in 3.33.2.1); from 3.34.0, before 3.36.3 (fixed in 3.36.3)

Published 2026-06-19. Last modified 2026-08-13.