Intel

AIKIDO-2026-505281

pypdf is vulnerable to Denial of Service (DoS)

Denial of Service (DoS)GHSA-fwg2-594c-jp42 Published Aug 10, 2026

48

Medium Risk

This Affects:

PYTHONpypdf
0.0.1 - 6.14.2
Fixed in 6.15.0
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TL;DR

pypdf parses CID font width information when loading fonts, for example during text extraction. A crafted PDF can declare font width entries with unusually large range and count values. Parsing these values allocates and iterates over oversized structures, causing long runtimes and large memory consumption. The fix limits the accepted CID width range and width count when loading fonts.

Who does this affect?

You are affected if you are using a version that falls within the vulnerable range and you extract text from PDF documents whose embedded fonts can carry untrusted CID width data.

Background info

pypdf is vulnerable to Denial of Service (DoS) in versions 0.0.1 - 6.14.2.

How to fix this

Upgrade the pypdf library to the patch version.