CVE-2021-42716: Fedoraproject Fedora

High severity, CVSS 7.1. EPSS: 1.5% chance of exploitation in the next 30 days.

An issue was discovered in stb stb_image.h 2.27. The PNM loader incorrectly interpreted 16-bit PGM files as 8-bit when converting to RGBA, leading to a buffer overflow when later reinterpreting the result as a 16-bit buffer. An attacker could potentially have crashed a service using stb_image, or read up to 1024 bytes of non-consecutive heap data without control over the read location.

Affected products

• Fedoraproject Fedora: version 33 only; version 34 only; version 35 only
• Nothings Stb Image.h: version 2.27 only

Published 2021-10-21. Last modified 2026-06-17.