CVE-2026-22690

Updated on 10 Jan 2026

Severity

2.7 Low severity

Details

CVSS score
2.7
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Overview

About vulnerability

Impact

An attacker who exploits this vulnerability can craft a PDF which leads to possibly long runtimes for actually invalid files. This can be achieved by omitting the /Root entry in the trailer, while using a rather large /Size value. Only the non-strict reading mode is affected.

Patches

This has been fixed in pypdf==6.6.0.

Workarounds

from pypdf import PdfReader, PdfWriter

# Instead of
reader = PdfReader("file.pdf")
# use the strict mode:
reader = PdfReader("file.pdf", strict=True)

# Instead of
writer = PdfWriter(clone_from="file.pdf")
# use an explicit strict reader:
writer = PdfWriter(clone_from=PdfReader("file.pdf", strict=True))

Resources

This issue has been fixed in #3594.

Details

Affected product:
pypdf
Affected packages:
pypdf @ 5.9.0