CVE-2026-104723: Insecure Deserialization (CVSS 8.8)

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.

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CVSS v3.1 Score

8.8

HIGH

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS — Exploit Prediction

0.0045

Probability of exploitation

0.37%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-502 Deserialization of Untrusted Data

References

Other References

https://plugins.trac.wordpress.org/browser/lifterlms/tags/10.2.1/includes/admin/class.llms.admin.builder.php#L1218 https://plugins.trac.wordpress.org/browser/lifterlms/tags/10.2.1/includes/admin/class.llms.admin.builder.php#L1576 https://plugins.trac.wordpress.org/browser/lifterlms/tags/10.2.1/includes/admin/class.llms.admin.builder.php#L458 https://plugins.trac.wordpress.org/browser/lifterlms/tags/10.2.1/includes/admin/class.llms.admin.builder.php#L993 https://plugins.trac.wordpress.org/changeset/3729229/lifterlms/trunk/includes/admin/class.llms.admin.builder.php https://www.wordfence.com/threat-intel/vulnerabilities/id/cc7893ee-414d-4796-bb34-4d83951b95bd?source=cve

Frequently Asked Questions

What is CVE-2026-104723? +

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. It has a CVSS v3.1 base score of 8.8 (HIGH).

How severe is CVE-2026-104723? +

CVE-2026-104723 has a CVSS v3.1 score of 8.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0045, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-104723? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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