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

- 種別: advisory
- 重大度: high
- 関連技術: python
- CVE: CVE-2026-96643
- 公開日時: 2026-10-22T16:02:39.000Z
- 情報源: GitHub Advisory Database (https://github.com/advisories/GHSA-g4qv-2jxx-769h)
- パーマリンク: https://vulnpulse.app/items/ghsa-ghsa-g4qv-2jxx-769h

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…