Pillow: PNG eXIf chunk makes EXIF parsing run in quadratic time

影響: pip:Pillow >= 11.0.0, < 13.0.0 → 13.0.0

A PNG file with a large eXIf chunk full of repeated 6-byte markers makes Pillow's EXIF parser take seconds of CPU instead of milliseconds. The cost grows with the square of the chunk size, so a normal small-photo-sized file is enough to cause real delay. ### Details Exif.load() in src/PIL/Image.py strips a marker from the start of the EXIF data like this: python while data and data.startswith(b"Exif\x00\x00"): data = data[6:] Each pass makes a new copy of the remaining data. A real camera write…

GitHub Advisory Databaseで読む

2026/10/23 01:02、GitHub Advisory Databaseが「Pillow: PNG eXIf chunk makes EXIF parsing run in quadratic time」を公開しました (種別: 脆弱性アドバイザリ)。重大度は「重要」(high) です。関連する技術: Python。CVE: CVE-2026-96643。