---
id: CVE-2026-41168
aliases:
  - GHSA-jj6c-8h6c-hppx
  - PYSEC-2026-3021
title: >-
  pypdf has long runtimes for wrong size values in cross-reference and object
  streams
summary: >-
  pypdf has long runtimes for wrong size values in cross-reference and object
  streams
severity: medium
cvss: 5.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'
vendor: pypdf
product: pypdf
ecosystem: pip
affected:
  - pypdf < 6.10.1
patched:
  - pypdf 6.10.1
published: '2026-04-15'
updated: '2026-09-10'
sourceUpdated: '2026-09-10T03:50:44.569518277Z'
source: OSV
sourceUrl: 'https://osv.dev/vulnerability/GHSA-jj6c-8h6c-hppx'
references:
  - url: 'https://github.com/py-pdf/pypdf/security/advisories/GHSA-jj6c-8h6c-hppx'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-41168'
  - url: 'https://github.com/py-pdf/pypdf/pull/3733'
  - url: >-
      https://github.com/py-pdf/pypdf/commit/62338e9d36419cf193ccec7331784f45df1d70b3
  - url: 'https://github.com/py-pdf/pypdf'
  - url: 'https://github.com/py-pdf/pypdf/releases/tag/6.10.1'
tags:
  - osv
  - pip
epss: 0.00515
epssPercentile: 0.41423
ingestedAt: '2026-07-13T18:57:59.808Z'
---

## Overview

### Impact

An attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires cross-reference streams with wrong large `/Size` values or object streams with wrong large `/N` values.

### Patches

This has been fixed in [pypdf==6.10.1](https://github.com/py-pdf/pypdf/releases/tag/6.10.1).

### Workarounds

If you cannot upgrade yet, consider applying the changes from PR [#3733](https://github.com/py-pdf/pypdf/pull/3733).

## Affected packages

- `pypdf < 6.10.1`

## Remediation

Upgrade to a patched release:

- `pypdf 6.10.1`