Denial of Service Vulnerability in Pillow Python Imaging Library
CVE-2026-112406

8.7HIGH

Key Information:

Vendor

Python-pillow

Status
Pillow
Vendor
CVE Published:
19 October 2026

What is CVE-2026-112406?

The Pillow Python imaging library is vulnerable to a denial of service attack due to a flaw in its PDF page rewriting process. Versions 5.1.0 through 13.0.0 are affected by a logic error in the PdfParser.rewrite_pages() function, which does not correctly detect cycles in the page tree. This can lead to an infinite loop when a cyclic PDF is processed, causing a substantial CPU load and potentially rendering applications unresponsive. The issue can be mitigated by updating to version 13.0.0, where the vulnerability has been addressed.

Affected Version(s)

Pillow >= 5.1.0, < 13.0.0

References

https://github.com/python-pillow/Pillow/security/advisori...
x_refsource_CONFIRM
https://github.com/python-pillow/Pillow/commit/b3ebf20c69...
x_refsource_MISC
https://github.com/python-pillow/Pillow/releases/tag/13.0.0
x_refsource_MISC

CVSS V4

Score:
8.7
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.