CVE-2026-84309

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.

CVSS v3 5.5 MEDIUM

5.5^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 1.8 / Impact : 3.6

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://github.com/py-pdf/pypdf/commit/c9ba557d565d57c53a0b3a0be06c0a4c29b0559b	Patch
https://github.com/py-pdf/pypdf/pull/3964	Patch
https://github.com/py-pdf/pypdf/releases/tag/6.16.0	Release Notes
https://github.com/py-pdf/pypdf/security/advisories/GHSA-jp53-mhqp-8xcg	Patch Vendor Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:pypdf_project:pypdf:*:*:*:*:*:*:*:*

History

05 Oct 2026, 17:42

Type	Values Removed	Values Added
First Time		Pypdf Project Pypdf Project pypdf
CVSS	v2 : ~~unknown~~ v3 : ~~unknown~~	v2 : unknown v3 : 5.5
CPE		cpe:2.3:a:pypdf_project:pypdf::::::::
References	~~() https://github.com/py-pdf/pypdf/commit/c9ba557d565d57c53a0b3a0be06c0a4c29b0559b -~~	() https://github.com/py-pdf/pypdf/commit/c9ba557d565d57c53a0b3a0be06c0a4c29b0559b - Patch
References	~~() https://github.com/py-pdf/pypdf/pull/3964 -~~	() https://github.com/py-pdf/pypdf/pull/3964 - Patch
References	~~() https://github.com/py-pdf/pypdf/releases/tag/6.16.0 -~~	() https://github.com/py-pdf/pypdf/releases/tag/6.16.0 - Release Notes
References	~~() https://github.com/py-pdf/pypdf/security/advisories/GHSA-jp53-mhqp-8xcg -~~	() https://github.com/py-pdf/pypdf/security/advisories/GHSA-jp53-mhqp-8xcg - Patch, Vendor Advisory

Information

Published : 2026-09-01 20:17

Updated : 2026-10-05 17:42

NVD link : CVE-2026-84309

Mitre link : CVE-2026-84309

CVE.ORG link : CVE-2026-84309

JSON object : View

Products Affected

pypdf_project

pypdf

CWE

CWE-835

Loop with Unreachable Exit Condition ('Infinite Loop')

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