---
id: CVE-2026-84310
title: pypdf is a free and open-source pure-python PDF library
summary: >-
  pypdf is a free and open-source pure-python PDF library. Prior to 6.16.1, an
  attacker can craft a PDF that causes pypdf/_doc_common.py _get_outline to
  consume long runtimes and large amounts of memory when retrieving document
  outlines wi…
severity: medium
cwe:
  - CWE-405
  - CWE-834
  - CWE-770
vendor: pypdf
product: pypdf
affected:
  - pypdf < 6.16.1
patched:
  - pypdf 6.16.1
published: '2026-09-01'
updated: '2026-09-09'
sourceUpdated: '2026-09-09T16:49:20.627'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-84310'
references:
  - url: >-
      https://github.com/py-pdf/pypdf/commit/d91ab705fd81ed1a9cec175c6958600dea1a4942
    label: security-advisories@github.com
  - url: 'https://github.com/py-pdf/pypdf/pull/3966'
    label: security-advisories@github.com
  - url: 'https://github.com/py-pdf/pypdf/releases/tag/6.16.1'
    label: security-advisories@github.com
  - url: 'https://github.com/py-pdf/pypdf/security/advisories/GHSA-23w6-3w8w-8484'
    label: security-advisories@github.com
  - url: 'https://github.com/advisories/GHSA-23w6-3w8w-8484'
  - url: 'https://github.com/py-pdf/pypdf'
  - url: 'https://pypi.org/project/pypdf'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-84310'
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-84310.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-84310'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2527049'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-84310'
tags:
  - nvd
  - ghsa
  - pip
  - osv
  - csaf
  - vex
  - red-hat
epss: 0.00182
epssPercentile: 0.0696
aliases:
  - GHSA-23w6-3w8w-8484
  - PYSEC-2026-3910
ecosystem: pip
ingestedAt: '2026-09-01T21:32:41.430Z'
cvss: 5.5
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H'
cvssSource: vendor
---

## Overview

pypdf is a free and open-source pure-python PDF library. Prior to 6.16.1, an attacker can craft a PDF that causes pypdf/_doc_common.py _get_outline to consume long runtimes and large amounts of memory when retrieving document outlines with large numbers of entries or deeply nested reused paths because the traversal lacked global entry-count and nesting-depth limits. This issue is fixed in version 6.16.1.

## Remediation

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

## Package advisory (CVE-2026-84310)

Affected packages:

- `pypdf < 6.16.1`

Patched in:

- `pypdf 6.16.1`

Source: https://github.com/advisories/GHSA-23w6-3w8w-8484

## Vendor advisories

- **Red Hat VEX** · Moderate · affected: Ansible Automation Orchestrator 2026, Exploit Intelligence, Lightspeed Core, OpenShift Lightspeed, Red Hat Ansible Automation Platform 2, Red Hat Enterprise Linux AI (RHEL AI) 3, … · no fix planned: Exploit Intelligence, Red Hat Ansible Automation Platform 2, Red Hat Quay 3, Ansible Automation Orchestrator 2026, … · updated 2026-09-25 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-84310.json)