Tutor LMS <= 4.0.7 — Authenticated (Subscriber+) PHP Object Injection to Remote Code Execution

Am I affected?

• Check your version: in wp-admin go to Plugins → Installed Plugins and read the version under Tutor LMS – eLearning and online course solution.
• No admin access? Run a passive check of your site. It reads public files only.

What to do

1. Update to version 4.0.8, or a newer patched version
2. Rotate administrator passwords and application secrets if the site ran a vulnerable version while publicly reachable.
3. Watch Tutor LMS – eLearning and online course solution to get an email when the next vulnerability is published.

Advisory

Source description from Wordfence Intelligence, credited to Chloe Chamberland, Wordfence Argus.

The Tutor LMS – eLearning and online course solution plugin for WordPress is vulnerable to PHP Object Injection in all versions up to, and including, 4.0.7 via the `withdraw_method_field` parameter of the `tutor_save_withdraw_account` AJAX handler. This is due to the handler lacking any capability or role check, relying solely on a nonce, while also passing attacker-supplied values through `esc_sql()`, which replaces every `%` character with a 66-byte HMAC placeholder token before the data is serialized and stored via `update_user_meta()`; when the meta is later retrieved, the placeholder is collapsed back to a single `%`, leaving serialized string length declarations 65 bytes greater than the actual content, and because array keys originate from entirely unescaped POST field names, `unserialize()` over-reads into attacker-controlled bytes, allowing injection of an arbitrary serialized object stream. This makes it possible for authenticated attackers, with subscriber-level access and above, to achieve remote code execution on the server by triggering the `GuzzleHttp\Cookie\FileCookieJar` POP chain, reachable via the `spl_autoload_register` loader in `TUTOR\RestAPI` which loads the plugin's own bundled PayPal Composer autoloader, writing attacker-controlled content to an attacker-specified filename. This has an unauthenticated pathway when user registration is enabled, which is common for students and teachers to register, and it requires the monetization feature to be enabled.

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 11, 2026

   CVE published

   Severity high, CVSS 8.8

2. Nov 13, 2026

   Record last updated