High severity · published Oct 19, 2026
CVE-2026-112406
Pillow: Infinite loop in PdfParser.rewrite_pages on page tree Parent cycle
7.5
CVSS
0.4%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 36% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
PI
Pillow · python-pillow
>= 5.1.0, < 13.0.0 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-112406
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-112406
Patch
https://github.com/python-pillow/Pillow/commit/b3ebf20c694f2f12537a629c30229a1d5a53f777
Release Notes
https://github.com/python-pillow/Pillow/releases/tag/13.0.0
Exploit
https://github.com/python-pillow/Pillow/security/advisories/GHSA-f2g6-542v-9j58
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