Rocket.Chat: Stored XSS in any message (leads to priv esc for all users and file leak + rce via electron app)

Persistent XSS flaw using nested markdown tags allows remote attacker to inject arbitrary JavaScript to message. This flaw leads to arbitrary file read and RCE on Rocket.Chat desktop app. Patched on 3.11, 3.10.5, 3.9.7, 3.8.8.