CVEvulnerability

CVE-2026-96640

8.2 HIGH Published 2026-10-21 Modified 2026-10-28 Official page ↗
Status
Modified
Published
2026-10-21
Last modified
2026-10-28
Assigner
[email protected]
CVSS 4.0 ([email protected])
8.2 HIGH — CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS 3.1 ([email protected])
7.5 HIGH — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weaknesses
CWE-400, CWE-407

Description

Pillow is a Python imaging library. From 5.1.0 until 13.0.0, PdfParser.linearize_page_tree() in src/PIL/PdfParser.py treats a PDF /Pages graph as a tree without tracking duplicate indirect references. When Image.save(..., format="PDF", append=True) processes an attacker-controlled existing PDF whose /Kids arrays repeatedly reference the same child /Pages node, Pillow expands the shared subtree as distinct pages. A compact malformed PDF can therefore create exponentially many page references and consume disproportionate CPU before the append completes. This issue is fixed in version 13.0.0.

Affected configurations

• python pillow (>= 5.1.0 < 13.0.0)

Related

Weakness · CWE (2)

  • CWE-400 Uncontrolled Resource Consumption weakness
  • CWE-407 Inefficient Algorithmic Complexity weakness

References