SOGo before 5.12.13 contains an improper restriction of excessive authentication attempts vulnerability that allows unauthenticated attackers to reset account passwords by repeatedly guessing secret-question answers via the passwordRecoveryCheck endpoint without lockout or rate limiting. Attackers can submit unlimited candidate answers to obtain a valid recovery JWT, then use it to change the account password without the old credential and log in via the connect endpoint, achieving full account takeover on accounts without TOTP enabled.