---
id: CVE-2026-113789
title: 'pypdf: Possible long runtimes/large memory usage when retrieving form fields'
summary: >-
  pypdf is a free and open-source pure-python PDF library. Prior to 6.21.0, an
  attacker can craft a PDF that causes large memory usage or long runtimes when
  an application retrieves the document's form fields. This issue is fixed in
  versio…
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'
cvssSource: cna
cwe:
  - CWE-400
  - CWE-407
vendor: py-pdf
product: pypdf
affected:
  - pypdf < 6.21.0
published: '2026-10-21'
updated: '2026-10-21'
sourceUpdated: '2026-10-21T15:33:45.801Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-113789'
references:
  - url: 'https://github.com/py-pdf/pypdf/security/advisories/GHSA-6vvc-x485-93v7'
    label: 'https://github.com/py-pdf/pypdf/security/advisories/GHSA-6vvc-x485-93v7'
  - url: 'https://github.com/py-pdf/pypdf/pull/4219'
    label: 'https://github.com/py-pdf/pypdf/pull/4219'
  - url: >-
      https://github.com/py-pdf/pypdf/commit/5ef728f0e16d225c853e89f861ba0a67402fe3f2
    label: >-
      https://github.com/py-pdf/pypdf/commit/5ef728f0e16d225c853e89f861ba0a67402fe3f2
  - url: 'https://github.com/py-pdf/pypdf/releases/tag/6.21.0'
    label: 'https://github.com/py-pdf/pypdf/releases/tag/6.21.0'
tags:
  - cve.org
ingestedAt: '2026-10-21T16:05:17.699Z'
---

## Overview

pypdf is a free and open-source pure-python PDF library. Prior to 6.21.0, an attacker can craft a PDF that causes large memory usage or long runtimes when an application retrieves the document's form fields. This issue is fixed in version 6.21.0.

## Affected

- `pypdf < 6.21.0`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.