The E2EE password entropy generated by Rocket.Chat Mobile prior to version 4.5.1 is insufficient, allowing attackers to crack it if they have the appropriate time and resources.
Rocket.Chat 6.12.0, 6.11.2, 6.10.5, 6.9.6, 6.8.6, 6.7.8, and before is vulnerable to a message forgery / impersonation issue. Attackers can abuse the UpdateOTRAck method to send ephemeral messages as if they were any other user they choose.
Rocket.Chat version 0.8.0 and newer is vulnerable to XSS in the markdown link parsing code for messages.