CVE-2026-96643

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

Description

Pillow is a Python imaging library. From 11.0.0 until 13.0.0, Exif.load() in src/PIL/Image.py repeatedly slices the remaining EXIF data while it begins with the six-byte Exif header. src/PIL/PngImagePlugin.py accepts an uncapped PNG eXIf chunk, so a file filled with repeated headers causes a new shrinking copy on every iteration and quadratic CPU work. The condition is reachable through Image.getexif(), Image._getexif(), and ImageOps.exif_transpose(), including common photo-upload rotation workflows. This issue is fixed in version 13.0.0.

Scores

Weaknesses (CWE)

• CWE-407

Advisories

• GHSA-g4qv-2jxx-769h — Pillow: PNG eXIf chunk makes EXIF parsing run in quadratic time
• PYSEC-2026-4342 — Pillow is a Python imaging library. From 11.0.0 until 13.0.0, Exif.load() in src/PIL/Image.py repeatedly slices the remaining EXIF data while it begins with the

European references

• ENISA EUVD · EUVD-2026-107564
• GCVE · GCVE-0-2026-96643

Affected configurations (NVD CPE)

• cpe:2.3:a:python:pillow:*:*:*:*:*:*:*:* ≥ 11.0.0 < 13.0.0

Affected products

References

• https://github.com/python-pillow/Pillow/security/advisories/GHSA-g4qv-2jxx-769h
• https://github.com/python-pillow/Pillow/pull/10073
• https://github.com/python-pillow/Pillow/commit/806e38381c781f32bbd22f4cd026678acd40fd6c
• https://github.com/python-pillow/Pillow/releases/tag/13.0.0

Sources