CVE-2026-104723 LifterLMS <= 10.2.1 - Authenticated (Custom+) PHP Object Injection via 'custom' Lesson Data
Authenticated attackers can inject PHP objects via lesson data, potentially leading to code execution or data access if a POP chain exists.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-104723?
CVE-2026-104723 is a high-severity unsafe deserialization vulnerability in LifterLMS – WP LMS for eLearning, Online Courses, & Quizzes, published on 10 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official 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.
Weakness: CWE-502
Which versions are affected by CVE-2026-104723?
How do I fix CVE-2026-104723?
No fix has been published for CVE-2026-104723 yet. Limit exposure of the affected software until one is available.
Upgrade, and only deserialise data from trusted sources or with an allow-list of types. More about Unsafe deserialization.
Is CVE-2026-104723 being exploited?
There is no known exploitation of CVE-2026-104723 in the wild and no public exploit code.
Sources
Also known as GHSA-5m5m-xm33-gpq9.