OTP Login & Register Woocommerce <= 2.7.2 — Unauthenticated Authentication Bypass via Brute Force

Am I affected?

• Check your version: in wp-admin go to Plugins → Installed Plugins and read the version under OTP Login & Register Woocommerce.
• No admin access? Run a passive check of your site. It reads public files only.
• No account is needed to exploit this. Treat any exposed site on an affected version as at risk.

What to do

1. Update to version 2.7.3, or a newer patched version
2. Rotate administrator passwords and application secrets if the site ran a vulnerable version while publicly reachable.
3. Watch OTP Login & Register Woocommerce to get an email when the next vulnerability is published.

Advisory

Source description from Wordfence Intelligence, credited to d4ngvn.

The OTP Login & Register Woocommerce plugin for WordPress is vulnerable to Authentication Bypass via OTP Brute Force in all versions up to, and including, 2.7.2. The vulnerability exists because the OTP rate-limit attempt counter in `process_otp_form` is keyed exclusively on the attacker-controlled `xoo_ml_user_ip_data` cookie's `ip_address` field, allowing unlimited counter resets by simply rotating the cookie, while the OTP itself is generated with PHP's non-cryptographic `rand()` function over a default space of only 9,000 possible values (1000–9999), and both the OTP issuance endpoint (`xoo_ml_login_with_otp`) and verification endpoint (`xoo_ml_otp_form_submit`) are registered as unauthenticated `wp_ajax_nopriv` actions with no nonce or capability checks. This makes it possible for unauthenticated attackers to brute-force the OTP for any registered account and obtain a full WordPress authentication session — including for administrator accounts — via `wp_set_auth_cookie()` in `login_user_with_otp()`. Exploitation requires the attacker to know the target user's registered phone number, which is used to trigger OTP issuance via the unauthenticated `xoo_ml_login_with_otp` endpoint.

Exploits & references

Proof-of-concept & detection

No public proof-of-concept or detection template is known for this vulnerability.

Advisories & patches

• Advisorywordfence.com

Related CVEs

Timeline

1. Sep 10, 2026

   CVE published

   Severity medium, CVSS 5.3

2. Nov 13, 2026

   Record last updated