CVE-2026-55380: Python Pillow

High severity, CVSS 7.5. EPSS: 0.4% chance of exploitation in the next 30 days.

Pillow is a Python imaging library. Prior to 12.3.0, PIL/GdImageFile.py GdImageFile._open() read image dimensions from the GD 2.x header and stored them in self._size without calling Image._decompression_bomb_check(), allowing a crafted .gd file to trigger excessive C-heap allocation when loaded. This issue is fixed in version 12.3.0.

Affected products

• Python Pillow: before 12.3.0 (fixed in 12.3.0)

Published 2026-07-06. Last modified 2026-07-07.