CVE-2026-88593

kkFileView 5.0.0 through 5.0.2 allows reflected XSS via the /onlinePreview endpoint. The OnlinePreviewController passes the user-controlled page and kkagent request parameters to FreeMarker templates without sanitization, and the templates insert these values into raw JavaScript contexts.

• Published Sep 16, 2026
• CVSS 6.1 medium
• 0.3% chance of exploitation in the next 30 days (EPSS)

CVE-2026-88593 at the National Vulnerability Database