CVE-2026-112406

Pillow is a Python imaging library. From 5.1.0 until 13.0.0, Pillow can enter an infinite loop while rewriting PDF pages. PdfParser.rewrite_pages() follows Parent relationships without detecting a cycle in the page tree. An attacker can supply a cyclic PDF to an application that appends an image to that PDF. This can hold the worker at full 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-835

Affected products

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

References

• https://github.com/python-pillow/Pillow/security/advisories/GHSA-f2g6-542v-9j58
• https://github.com/python-pillow/Pillow/commit/b3ebf20c694f2f12537a629c30229a1d5a53f777
• https://github.com/python-pillow/Pillow/releases/tag/13.0.0