Memory leak in pngrutil.c in libpng before 1.2.44, and 1.4.x before 1.4.3, allows remote attackers to cause a denial of service (memory consumption and application crash) via a PNG image containing malformed Physical Scale (aka sCAL) chunks.
The product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse.