CVE-2026-78465 Gimp: integer overflow in pcx loader (planes=4) leads to heap overflow on 32-bit

A flaw was found in the file-pcx plugin in GIMP, affecting 32-bit builds only. When processing a PCX image file, the plugin calculates memory allocation sizes based on the image dimensions and the number of color planes. If a crafted file sets the number of planes to 4 alongside sufficiently larg...