CVE-2026-101203: Faststone Image Viewer

Medium severity, CVSS 6.3. EPSS: 0.2% chance of exploitation in the next 30 days.

A vulnerability has been found in FastStone Image Viewer up to 8.3. The impacted element is an unknown function of the component 1bpp RLE Decoder. The manipulation leads to out-of-bounds write. The attack can be initiated remotely. The vendor was contacted early about this disclosure but did not respond in any way.

Affected products

• Faststone Image Viewer: version 8.0 only; version 8.1 only; version 8.2 only; version 8.3 only

Published 2026-09-28. Last modified 2026-09-29.