A missing link validation in Nextcloud Server before 20.0.2, 19.0.5, 18.0.11 allows execution of a stored XSS attack using Internet Explorer when saving a 'javascript:' URL in markdown format.
Exploitability
AV:NAC:LPR:LUI:RScope
S:CImpact
C:LI:LA:N5.4/CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:NInjection