---
id: CVE-2026-113791
aliases:
  - GHSA-cgf9-327m-v77c
title: 'pypdf: Possible large memory usage when parsing content streams'
summary: 'pypdf: Possible large memory usage when parsing content streams'
severity: medium
cvss: 6
cvssVector: 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'
vendor: pypdf
product: pypdf
ecosystem: pip
affected:
  - pypdf < 6.21.0
patched:
  - pypdf 6.21.0
published: '2026-10-22'
updated: '2026-10-22'
sourceUpdated: '2026-10-22T17:00:04.215115256Z'
source: OSV
sourceUrl: 'https://osv.dev/vulnerability/GHSA-cgf9-327m-v77c'
references:
  - url: 'https://github.com/py-pdf/pypdf/security/advisories/GHSA-cgf9-327m-v77c'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-113791'
  - url: 'https://github.com/py-pdf/pypdf/pull/4218'
  - url: >-
      https://github.com/py-pdf/pypdf/commit/18bd2981a74479483a0b9507602c58a63d6c9b12
  - url: 'https://github.com/py-pdf/pypdf'
  - url: 'https://github.com/py-pdf/pypdf/releases/tag/6.21.0'
  - url: 'https://github.com/advisories/GHSA-cgf9-327m-v77c'
tags:
  - osv
  - pip
  - ghsa
  - cve.org
epss: 0.00392
epssPercentile: 0.33135
cvssSource: cna
cwe:
  - CWE-400
  - CWE-770
ingestedAt: '2026-10-21T16:05:17.697Z'
---

## Overview

### Impact

An attacker who uses this vulnerability can craft a PDF which leads to large memory usage. This requires parsing content streams with many small operations.

### Patches

This has been fixed in [pypdf==6.21.0](https://github.com/py-pdf/pypdf/releases/tag/6.21.0).

### Workarounds

If you cannot upgrade yet, consider applying the changes from PR [#4218](https://github.com/py-pdf/pypdf/pull/4218).

## Affected packages

- `pypdf < 6.21.0`

## Remediation

Upgrade to a patched release:

- `pypdf 6.21.0`