Zulip from 8.0 to 8.3 contains a memory leak vulnerability in the handling of popovers.
https://github.com/zulip/zulip/commit/0a90a13becbf0338a8fc1ad37946e51c2c25b0a5
https://github.com/zulip/zulip/blob/8.3/web/src/click_handlers.js
https://gist.github.com/1047524396/f7ff51d24ebbb29e21dfb70a0c97302b