Envoy is a high-performance edge/middle/service proxy. The regex expression is compiled for every request and can result in high CPU usage and increased request latency when multiple routes are configured with such matchers. This issue has been addressed in released 1.29.1, 1.28.1, 1.27.3, and 1.26.7. Users are advised to upgrade. There are no known workarounds for this vulnerability.
Exploitability
AV:NAC:LPR:NUI:RScope
S:UImpact
C:NI:NA:L4.3/CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:LOther
Resource Management