CVE-2026-112894

Pillow is a Python imaging library. From 5.1.0 until 13.0.0, Pillow takes quadratic time to reserve PDF object identifiers when saving many frames with save_all enabled. PdfParser.next_object_id() repeatedly rebuilds and scans all previously reserved identifiers for every object. An attacker can supply a multi-frame image, including a small APNG with a large declared frame count, to an application that converts it to a multipage PDF. This can consume excessive CPU and deny service. This issue is fixed in version 13.0.0.

Score

CVSS 4.0 8.7 High

Status

Analyzed - security-advisories@github.com

Published

2026-10-19

Last modified

2026-10-27

Weaknesses

CWE-407

Affected products

• Pillow (Python)
• Pillow (Python-pillow)

References

• https://github.com/python-pillow/Pillow/security/advisories/GHSA-jg86-v3jv-hrpm
• https://github.com/python-pillow/Pillow/commit/f6a852555f1a1bdff7781abf25f1a3b8bd6ce6cb
• https://github.com/python-pillow/Pillow/releases/tag/13.0.0