Description
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.
Published: 2026-09-12
Score: 8.8 High
EPSS: < 1% Very Low
KEV: No
Impact: Remote Code Execution
Action: Immediate Patch
AI Analysis

Impact

The Tutor LMS plugin contains a PHP Object Injection flaw that allows an attacker to craft manipulated serialized data. The vulnerability arises because the withdraw endpoint serializes untrusted request data and stores it in user meta, leading to deserialization of attacker‑supplied objects. Exploiting this weakness can lead to other library chains, notably GuzzleHttp\Cookie\FileCookieJar, and ultimately to the execution of arbitrary code on the WordPress server. The vulnerability addresses the weakness identified as CWE‑502.

Affected Systems

The flaw affects the Tutor LMS – eLearning and online course solution plugin released by Themeum. All releases up to and including version 4.0.7 are impacted, while newer releases are presumed to contain a patch.

Risk and Exploitability

The vulnerability carries a CVSS score of 8.8, classifying it as high severity. The EPSS score is below 1%, indicating a low likelihood of current exploitation. It is not yet listed in the CISA KEV catalog. Attackers must either be authenticated subscribers or gain unauthenticated access when user registration is enabled and monetization is active. Once the conditions are met, the attacker can trigger the malicious object chain via the withdrawal API, achieving remote code execution on the host.

Generated by OpenCVE AI on September 12, 2026 at 15:50 UTC.

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

  • Upgrade Tutor LMS to a version newer than 4.0.7 that addresses this issue.
  • Disable the withdrawal or monetization features if they are not required for your site.
  • Restrict the withdrawal API to administrator roles or remove the capability checks for lower‑privileged users.

Generated by OpenCVE AI on September 12, 2026 at 15:50 UTC.

Tracking

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Advisories

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History

Sat, 12 Sep 2026 07:45:00 +0000

Type Values Removed Values Added
Description 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.
Title Tutor LMS <= 4.0.7 - Authenticated (Subscriber+) PHP Object Injection to Remote Code Execution
Weaknesses CWE-502
References
Metrics cvssV3_1

{'score': 8.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}

Subscriptions

No data.

cve-icon MITRE

Status: PUBLISHED

Assigner: Wordfence

Published:

Updated: 2026-09-12T07:39:15.920Z

Reserved: 2026-08-23T15:39:15.798Z

Link: CVE-2026-78175

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-12T08:16:24.507

Modified: 2026-09-12T08:16:24.507

Link: CVE-2026-78175

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-12T16:00:14Z

Weaknesses
  • CWE-502

    Deserialization of Untrusted Data