pypdf is a free and open-source pure-python PDF library. Prior to 6.16.0, an attacker can craft a PDF whose cyclic tree structure causes pypdf/generic/_data_structures.py TreeObject.insert_child to follow /Next links indefinitely when a writing code path inserts a child, producing an infinite loop. This issue is fixed in version 6.16.0.
History

Thu, 03 Sep 2026 12:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H'}

threat_severity

Moderate


Wed, 02 Sep 2026 10:45:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Wed, 02 Sep 2026 02:30:00 +0000

Type Values Removed Values Added
First Time appeared Py-pdf
Py-pdf pypdf
Vendors & Products Py-pdf
Py-pdf pypdf

Tue, 01 Sep 2026 22:00:00 +0000

Type Values Removed Values Added
Description pypdf is a free and open-source pure-python PDF library. Prior to 6.16.0, an attacker can craft a PDF whose cyclic tree structure causes pypdf/generic/_data_structures.py TreeObject.insert_child to follow /Next links indefinitely when a writing code path inserts a child, producing an infinite loop. This issue is fixed in version 6.16.0.
Title pypdf: Possible infinite loop for TreeObject.insert_child
Weaknesses CWE-835
References
Metrics cvssV4_0

{'score': 6.9, 'vector': 'CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2026-09-01T19:58:46.266Z

Updated: 2026-09-02T13:41:31.258Z

Reserved: 2026-09-01T16:17:43.079Z

Link: CVE-2026-84309

cve-icon Vulnrichment

Updated: 2026-09-02T13:41:27.469Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-09-01T20:17:25.027

Modified: 2026-09-09T16:49:20.627

Link: CVE-2026-84309

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-09-01T19:58:46Z

Links: CVE-2026-84309 - Bugzilla