CVE-2026-112406 PUBLISHED

Pillow: Infinite loop in PdfParser.rewrite_pages on page tree Parent cycle

Assigner: GitHub_M
Reserved: 19.10.2026 Published: 19.10.2026 Updated: 19.10.2026

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.

Metrics

CVSS 4.0

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
CVSS Score: 8.7

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	None	Confidentiality	None
Attack Complexity	Low	Integrity	None	Integrity	None
Attack Requirements	None	Availability	High	Availability	None
Privileges Required	None
User Interaction	None

CVSS 4.0

Product Status

Vendor	python-pillow
Product	Pillow
Versions	Version >= 5.1.0, < 13.0.0 is affected

References

Problem Types

CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop') CWE