CVE-2021-26233: Faststone Image Viewer

High severity, CVSS 7.8. EPSS: 1.1% chance of exploitation in the next 30 days.

FastStone Image Viewer <= 7.5 is affected by a user mode write access violation near NULL at 0x005bdfcb, triggered when a user opens or views a malformed CUR file that is mishandled by FSViewer.exe. Attackers could exploit this issue for a Denial of Service (DoS) or possibly to achieve code execution.

Affected products

• Faststone Image Viewer: up to and including 7.5

Published 2021-03-18. Last modified 2026-06-17.