Listmonk 6.0.0 before 7.0.0-beta.2 contains a 2FA bypass vulnerability that allows attackers with a valid password to brute-force TOTP codes because the attempt counter resets on every new password login. Attackers can repeatedly submit credentials to POST /admin/login to obtain fresh tokens, each allowing 15 more guesses, gaining sessions for 2FA-protected accounts including Super Admin.
CWE-307