Envoy is an open source edge and service proxy, designed for cloud-native applications. In affected versions a crafted request crashes Envoy when a CONNECT request is sent to JWT filter configured with regex match. This provides a denial of service attack vector. The only workaround is to not use regex in the JWT filter. Users are advised to upgrade.
https://github.com/envoyproxy/envoy/security/advisories/GHSA-vj5m-rch8-5r2p
https://github.com/envoyproxy/envoy/commit/9371333230b1a6e1be2eccf4868771e11af6253a