CVE-2026-63233
A critical flaw in Koollab LMS lets an authenticated user run arbitrary code on the server. The bug combines SQL injection with unsafe deserialization, allowing the attacker to write a webshell to a public directory. This can give full control over the affected system.
No official fix yet. If none appears within 45 days of first tracking, this entry is removed automatically.
Who is affected
Koollab Learning Management System (any version).
Real-world impact
An attacker who can log into the LMS can inject malicious SQL, cause the application to unserialize attacker‑controlled data, and write a webshell to a publicly accessible folder. Once the webshell is in place, the attacker can run any commands on the server, effectively taking over the machine.
Why this severity
The CVSS score of 9.9 reflects that the vulnerability can be exploited over the network (AV:N), requires only low effort (AC:L) and a low privilege level (PR:L). No user interaction is needed (UI:N), and the attack changes the system’s scope (S:C), compromising confidentiality, integrity, and availability (C:H/I:H/A:H).
What to do about it
No official fix or mitigation is documented in the sources yet. Monitor the vendor advisory and apply the patch as soon as it is released.
No fix documented in sources