Successful exploitation of the stored cross-site scripting (XSS) vulnerability could allow an attacker to execute arbitrary JavaScript on any user account that has access to Koollab LMS’ courselet feature
Source GCVE Database
Not known to be exploited · CVSS 5.4 Medium.
Data as of 27 Oct 2026, 00:07 UTC
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:NExploitation evidence
Disclosed: evidence found.
CVE published 23 Apr 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Three LearningKoollab Learning Management System | Affected
| Fixed in– |
Description
Successful exploitation of the stored cross-site scripting (XSS) vulnerability could allow an attacker to execute arbitrary JavaScript on any user account that has access to Koollab LMS’ courselet feature.