CVE-2026-104732

The Advanced IP Blocker plugin for WordPress is vulnerable to Authentication Bypass in all versions up to, and including, 8.13.13 The vulnerability exists because handle_login_action() performs no server-side check — via transient, session marker, or equivalent — that a requester completed step-1 password authentication before processing a step-2 TOTP submission for the POSTed user_id; compounding this, an error branch in the function unconditionally mints a fresh advaipbl-2fa-interim-{user_id} nonce and delivers it in a Location header to any unauthenticated caller, after which display_2fa_login_form_step_2() renders a valid advaipbl-2fa-verify-{user_id} nonce in HTML — both nonces computed against a fixed uid=0 empty-session context and therefore fully reusable by the attacker across subsequent requests. This makes it possible for unauthenticated attackers to bypass authentication entirely for any 2FA-enabled account, including administrators, by brute-forcing an unthrottled 6-digit TOTP code (no attempt counter, no account lockout, and no wp_login_failed firing) and receiving a fully authenticated session cookie via wp_set_auth_cookie without ever supplying the account password, resulting in complete site takeover. Exploitation requires only a known user_id for an account that has the plugin's 2FA feature enabled.

The Advanced IP Blocker plugin for WordPress is vulnerable to Authentication Bypass in all versions up to, and including, 8.13.13 The vulnerability exists because handle_login_action() performs no server-side check — via transient, session marker, or equivalent — that a requester completed step-1 password authentication before processing a step-2 TOTP submission for the POSTed user_id; compounding this, an error branch in the function unconditionally mints a fresh advaipbl-2fa-interim-{user_id} nonce and delivers it in a Location header to any unauthenticated caller, after which display_2fa_login_form_step_2() renders a valid advaipbl-2fa-verify-{user_id} nonce in HTML — both nonces computed against a fixed uid=0 empty-session context and therefore fully reusable by the attacker across subsequent requests. This makes it possible for unauthenticated attackers to bypass authentication entirely for any 2FA-enabled account, including administrators, by brute-forcing an unthrottled 6-digit TOTP code (no attempt counter, no account lockout, and no wp_login_failed firing) and receiving a fully authenticated session cookie via wp_set_auth_cookie without ever supplying the account password, resulting in complete site takeover. Exploitation requires only a known user_id for an account that has the plugin's 2FA feature enabled.

The Advanced IP Blocker plugin for WordPress is vulnerable to Authentication Bypass in all versions up to, and including, 8.13.13 The vulnerability exists because handle_login_action() performs no server-side check — via transient, session marker, or equivalent — that a requester completed step-1 password authentication before processing a step-2 TOTP submission for the POSTed user_id; compounding this, an error branch in the function unconditionally mints a fresh advaipbl-2fa-interim-{user_id} nonce and delivers it in a Location header to any unauthenticated caller, after which display_2fa_login_form_step_2() renders a valid advaipbl-2fa-verify-{user_id} nonce in HTML — both nonces computed against a fixed uid=0 empty-session context and therefore fully reusable by the attacker across subsequent requests. This makes it possible for unauthenticated attackers to bypass authentication entirely for any 2FA-enabled account, including administrators, by brute-forcing an unthrottled 6-digit TOTP code (no attempt counter, no account lockout, and no wp_login_failed firing) and receiving a fully authenticated session cookie via wp_set_auth_cookie without ever supplying the account password, resulting in complete site takeover. Exploitation requires only a known user_id for an account that has the plugin's 2FA feature enabled.

The Advanced IP Blocker plugin for WordPress is vulnerable to Authentication Bypass in all versions up to, and including, 8.13.13 The vulnerability exists because handle_login_action() performs no server-side check — via transient, session marker, or equivalent — that a requester completed step-1 password authentication before processing a step-2 TOTP submission for the POSTed user_id; compounding this, an error branch in the function unconditionally mints a fresh advaipbl-2fa-interim-{user_id} nonce and delivers it in a Location header to any unauthenticated caller, after which display_2fa_login_form_step_2() renders a valid advaipbl-2fa-verify-{user_id} nonce in HTML — both nonces computed against a fixed uid=0 empty-session context and therefore fully reusable by the attacker across subsequent requests. This makes it possible for unauthenticated attackers to bypass authentication entirely for any 2FA-enabled account, including administrators, by brute-forcing an unthrottled 6-digit TOTP code (no attempt counter, no account lockout, and no wp_login_failed firing) and receiving a fully authenticated session cookie via wp_set_auth_cookie without ever supplying the account password, resulting in complete site takeover. Exploitation requires only a known user_id for an account that has the plugin's 2FA feature enabled.