CVE-2026-26308 Envoy has an RBAC Header Validation Bypass via Multi-Value Header Concatenation

Envoy is a high-performance edge/middle/service proxy. Prior to 1.37.1, 1.36.5, 1.35.8, and 1.34.13, the Envoy RBAC Role-Based Access Control filter contains a logic vulnerability in how it validates HTTP headers when multiple values are present for the same header name. Instead of validating eac...