Classified Listing — Mobile Number Verification <= 1.6.0 - Unauthenticated Authentication Bypass via Firebase OTP Login

Am I affected?

• Check your version: in wp-admin go to Plugins → Installed Plugins and read the version under Classified Listing - Mobile Number Verification.
• 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 1.7.0, or a newer patched version
2. Rotate administrator passwords and application secrets if the site ran a vulnerable version while publicly reachable.
3. Watch Classified Listing - Mobile Number Verification to get an email when the next vulnerability is published.

Advisory

Source description from Wordfence Intelligence, credited to Rafie Muhammad.

The Classified Listing - Mobile Number Verification plugin for WordPress is vulnerable to Authentication Bypass in all versions up to, and including, 1.6.0. This is due to missing server-side Firebase OTP validation in the process_otp_login() function. This makes it possible for unauthenticated attackers to authenticate as any user with a phone number registered in the plugin's phone table by submitting an arbitrary OTP code and UID through the Firebase OTP login flow. Successful exploitation requires OTP login to be enabled with Firebase selected as the verification gateway, and requires the attacker to know or guess the target account's registered phone number. Administrator account takeover is possible if an administrator account has a phone number registered in the plugin.

Exploits & references

Proof-of-concept & detection

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

Advisories & patches

• Advisorywordfence.com

Timeline

1. Aug 25, 2026

   CVE published

   Severity high, CVSS 8.1

2. Nov 13, 2026

   Record last updated