Pillow: Decompression Bomb DoS via PdfParser.PdfStream.decode()

Summary PdfParser.PdfStream.decode in Pillow's PdfParser.py calls zlib.decompress with the bufsize parameter set to the value of the PDF stream's Length field, without any upper bound on the actual decompressed output size. Python's zlib.decompress bufsize argument is an initial output buffer hin...

BIT-PILLOW-2026-59200 Pillow: Decompression Bomb DoS via PdfParser.PdfStream.decode()

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...