CVE-2021-26236: Faststone Image Viewer

High severity, CVSS 7.8. EPSS: 2% chance of exploitation in the next 30 days.

FastStone Image Viewer v.<= 7.5 is affected by a Stack-based Buffer Overflow at 0x005BDF49, affecting the CUR file parsing functionality (BITMAPINFOHEADER Structure, 'BitCount' file format field), that will end up corrupting the Structure Exception Handler (SEH). Attackers could exploit this issue to achieve code execution when a user opens or views a malformed/specially crafted CUR file.

Affected products

• Faststone Image Viewer: up to and including 7.5

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