BIT-PILLOW-2026-112891 Pillow: Quadratic GIF comment copying during save

Pillow is a Python imaging library. From 9.2.0 until 13.0.0, Pillow performs quadratic copying when saving a GIF with a long comment. getglobalheader repeatedly copies portions of comment data while assembling the global header, including comments retained from an untrusted input image. An attack...