Intel

AIKIDO-2026-562115

PyMuPDF is vulnerable to Integer Overflow

Integer OverflowCVE-2026-3308 Published Aug 13, 2026

78

High Risk

This Affects:

PYTHONPyMuPDF
1.17.0 - 1.27.2
Fixed in 1.28.0
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TL;DR

pdf_load_image_imp in pdf-image.c computes the unpack buffer size for PDF image pixel data with narrow integer arithmetic that can silently wrap for large or crafted width, height, or bit-depth values, even though a later sanity check assumes no overflow. The undersized size is then used to allocate the destination buffer, so unpacking the image overruns the heap. The fix uses overflow-safe size calculation before allocating the unpack buffer.

Who does this affect?

You are affected if you are using a version that falls within the vulnerable range and process PDF files from untrusted sources.

Background info

PyMuPDF is vulnerable to Integer Overflow in versions 1.17.0 - 1.27.2.

How to fix this

Upgrade the PyMuPDF library to the patch version.