CVE-2026-112891

Affected versions of the Pillow package are vulnerable to Inefficient Algorithmic Complexity due to repeated copying of comment data when saving GIF images. The `_get_global_header()` function processes long GIF comment blocks in a manner that results in quadratic time complexity, as portions of the comment are repeatedly copied rather than handled in a single pass. An attacker can exploit this by supplying a crafted GIF containing an unusually long comment to a service that automatically processes and resaves untrusted images in GIF format, causing excessive CPU consumption and resulting in a Denial of Service condition.