CVE-2026-59200: Python Pillow

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

Pillow is a Python imaging library. From 5.1.0 until 12.3.0, PdfParser.PdfStream.decode() in PIL/PdfParser.py calls zlib.decompress() with bufsize set to the PDF stream Length field without bounding the decompressed output size, allowing a crafted FlateDecode PDF stream to exhaust memory from a small file. This issue is fixed in version 12.3.0.

Affected products

• Python Pillow: from 5.1.0, before 12.3.0 (fixed in 12.3.0)

Published 2026-07-14. Last modified 2026-07-21.