CVE-2026-104723: lifterlms lifterlms – wp lms for elearning, online courses, & quizzes Deserialization of Untrusted Data

Vulnerability summary

CVE-2026-104723 is a high (CVSS 8.8) Deserialization of Untrusted Data vulnerability in lifterlms lifterlms – wp lms for elearning, online courses, & quizzes. EPSS estimates a 0.45% chance of exploitation in the next 30 days, higher than 37.8% of scored vulnerabilities. Fixed in 10.3.0.

Timeline

1. 10-10-2026
   PublishedVulnerability first disclosed.
2. 11-10-2026
   Last modifiedVulnerability information updated.

Description

The LifterLMS – WP LMS for eLearning, Online Courses, & Quizzes plugin for WordPress is vulnerable to PHP Object Injection in all versions up to, and including, 10.2.1 via deserialization of untrusted input . This makes it possible for authenticated attackers, with custom-level access and above, to inject a PHP Object. No known POP chain is present in the vulnerable software, which means this vulnerability has no impact unless another plugin or theme containing a POP chain is installed on the site. If a POP chain is present via an additional plugin or theme installed on the target system, it may allow the attacker to perform actions like delete arbitrary files, retrieve sensitive data, or execute code depending on the POP chain present. This vulnerability is only exploitable during lesson creation when a temporary lesson ID triggers the custom metadata path, and requires the attacker to hold a role with the edit_course capability, such as Instructor, Instructor's Assistant, LMS Manager, or Administrator.

• CWE-502Deserialization of Untrusted DataThe product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.