CVE Catalog

CVE-2026-96640

HighCVSS 7.5
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.58%

48th percentile - higher than 48% of all known CVEs

Summary

Pillow versions 5.1.0 through 13.0.0 fail to track duplicate indirect references in a PDF /Pages graph. A compact malformed PDF can cause exponentially many page references and disproportionate CPU consumption when Image.save with append=True processes an attacker-controlled PDF.

Risk Assessment

An attacker can supply a crafted PDF that, when processed by an application using Pillow, causes CPU resource exhaustion and service slowdown or denial of service.

Recommendation

Upgrade Pillow to version 13.0.0 or later. Consider limiting the size and complexity of PDF files processed from untrusted sources.

Other vulnerabilities in Pillow

See all
Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS