What is GHSA-w23x-9jrw-r45c?

GHSA-w23x-9jrw-r45c is a security advisory published by GitHub Security Advisories with High severity. pypdf: Possible large memory usage when retrieving alphabetical page labels

Which CVE IDs does GHSA-w23x-9jrw-r45c cover?

GHSA-w23x-9jrw-r45c covers the following CVE IDs: CVE-2026-103000. Each CVE has its own detail page on EchelonGraph Pulse with the synthesized EG score.

Which products are affected by GHSA-w23x-9jrw-r45c?

GHSA-w23x-9jrw-r45c affects 1 product, including: pip/pypdf:\u003c 6.19.0.

GHSA-w23x-9jrw-r45cHigh

pypdf: Possible large memory usage when retrieving alphabetical page labels

Vendor

GitHub Security Advisories

Published

October 1, 2026

Last Modified

October 1, 2026

🔗 CVE IDs covered (1)

CVE-2026-103000 →

📋 Description

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 alphabetical labels.

Patches

This has been fixed in pypdf==6.19.0.

Workarounds

If you cannot upgrade yet, consider applying the changes from PR #4096.

🎯 Affected products1

pip/pypdf:< 6.19.0

🔗 References (6)

https://github.com/py-pdf/pypdf/security/advisories/GHSA-w23x-9jrw-r45c
https://nvd.nist.gov/vuln/detail/CVE-2026-103000
https://github.com/py-pdf/pypdf/pull/4096
https://github.com/py-pdf/pypdf/commit/0d8b5a8832cde1ba308b5c27567b879b7b7eed4a
https://github.com/py-pdf/pypdf/releases/tag/6.19.0
https://github.com/advisories/GHSA-w23x-9jrw-r45c