Sun Oct 20 2019 06:47:15 UTC
It's not a bug. It's an undocumented feature.
Hide Search Description
ID Product Comp Assignee Status Resolution Summary Changed
59758 Tomcat 8 WebSocke dev NEW --- Add http proxy username-password credentials support for ClientEndpoint using system properties 2017-09-13
One bug found.

as

File a new bug in the "WebSocket" component of the "Tomcat 8" product