CVE-2026-63234: Three Learning Koollab Lms

Critical severity, CVSS 9.9. EPSS: 0.5% chance of exploitation in the next 30 days.

A SQL injection and unsafe deserialisation vulnerability in Koollab LMS allowed an authenticated attacker to inject through the manual mark assessment endpoint, control data passed to unserialize(), write a webshell to a publicly accessible location, and execute arbitrary code on the server.

Affected products

• Three Learning Koollab Lms: version 5.3.2 only

Published 2026-07-29. Last modified 2026-07-30.