CVE-2021-42716

An issue was discovered in stb stbimage.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 stbimage, or read up to 1024 bytes of non-consecutive heap data without control over the read location.