Mutt before 1.14.4 and NeoMutt before 2020-06-19 have a STARTTLS buffering issue that affects IMAP, SMTP, and POP3. When a server sends a "begin TLS" response, the client reads additional data (e.g., from a man-in-the-middle attacker) and evaluates it in a TLS context, aka "response injection."
Created mutt tracking bugs for this issue:
Affects: fedora-all [bug 1850171]
This has been fixed in following versions. Can we close this bug?
In reply to comment #4:
> This has been fixed in following versions. Can we close this bug?