CVE-2026-50873

Critical severity, CVSS 9.8. EPSS: 0.6% chance of exploitation in the next 30 days.

An arbitrary file upload vulnerability in the attachment handling component of flatnotes v5.5.4 allows attackers to execute arbitrary code via uploading a crafted HTML or SVG file.

Published 2026-06-15. Last modified 2026-06-17.