GHSA-qv6h-rv94-w285: Pip/pypdf vulnerability

Q: What must an attacker do to trigger the excessive memory consumption?

The attacker must supply a crafted PDF and cause the application to access that document's page labels. The issue is triggered when those page labels contain large Roman numerals.

Q: Which release fixes this issue?

The issue is fixed in pypdf 6.17.0.

Q: What can be done if upgrading is not immediately possible?

Consider applying the changes from PR #4047 as a workaround.

Published Oct 1, 2026

Updated

Impact

An attacker who uses this vulnerability can craft a PDF which leads to large memory consumption. This requires accessing the page labels of a document with large Roman numerals.

Patches

This has been fixed in pypdf==6.17.0.

Workarounds

If you cannot upgrade yet, consider applying the changes from PR #4047.

Affected Software

1 affected componentFixes available

pip/pypdf<6.17.0

6.17.0

Remediation

Recommended actions to resolve this vulnerability, in priority order.

Upgrade
Upgrade pip/pypdf to a version that resolves this vulnerability.
Fixed in 6.17.0
Upgrade
Upgrade pypdf to a version that resolves this vulnerability.
Fixed in 6.17.0
Compensating control
If you cannot upgrade, apply the changes from PR #4047.

Event History

Oct 1, 2026

Advisory Published

via GitHub·03:03 PM

Data Sourced

via GitHub·03:03 PM

DescriptionWeaknessAffected Software

Frequently Asked Questions

What must an attacker do to trigger the excessive memory consumption?

The attacker must supply a crafted PDF and cause the application to access that document's page labels. The issue is triggered when those page labels contain large Roman numerals.

Which release fixes this issue?