Progress Sitefinity 9.1 has XSS via file upload, because JavaScript code in an HTML file has the same origin as the application's own code. This is fixed in 10.1.
Severity
CVSS 3.0
5.4 medium
CVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
EPSS
0.7% chance of exploitation in the next 30 days; higher than 53% of CVEs (scores of 2026-10-31)