DoLogin Security EUVD-2026-42167

The DoLogin Security plugin for WordPress is vulnerable to Authentication Bypass via Insufficient Randomness in all versions up to, and including, 4.3. The vulnerability exists because dologin\s::rrand() seeds the Mersenne Twister with mt_srand((double) microtime() * 1000000) - discarding the integer-seconds component of microtime() and constraining the seed to a range of approximately 10^6 values (~20 bits of entropy) - after which every character of the 32-character magic-link token is drawn sequentially with mt_rand(), making the entire token a deterministic function of that seed. Because Pswdless::try_login() is registered on the unauthenticated init hook, resolves the target account by the auto-increment numeric ID embedded in the ?dologin=<id>.<hash> parameter, performs the hash comparison using a non-constant-time != operator, and then calls wp_set_auth_cookie() directly - never passing through wp_authenticate() and therefore never triggering the plugin's own Auth::_has_login_err() lockout - an unauthenticated attacker can brute-force the ~10^6-candidate seed space to reconstruct an active passwordless login token and authenticate as any targeted user, including administrators, without a password. Exploitation requires that a valid, unexpired passwordless login link (active for up to 7 days) exists for the target account at the time of the attack, and that the numeric link ID is known or guessable from the auto-increment primary key.