CVE-2026-84309CWE-835

CVE-2026-84309

Medium · published September 2, 2026

CVSS v3.1
5.5
EPSS
0%
Percentile
7.9
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
5.5 · MEDIUM
Vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
CVSS v4.0
6.9 · 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
EPSS
0.00187 · 7.9th percentile
Weakness
CWE-835 · Loop with Unreachable Exit Condition ('Infinite Loop')
Published
2026-09-02T00:17Z
Affected products (1)
ProductVersionsFixed in
pypdf_project/pypdf< 6.16.06.16.0
References (4)
https://github.com/py-pdf/pypdf/commit/c9ba557d565d57c53a0b3a0be06c0a4c29b0559b · [email protected]https://github.com/py-pdf/pypdf/pull/3964 · [email protected]https://github.com/py-pdf/pypdf/releases/tag/6.16.0 · [email protected]https://github.com/py-pdf/pypdf/security/advisories/GHSA-jp53-mhqp-8xcg · [email protected]
EPSS history
Timeline
  • 03 SEP 03:32Z
    EPSS moved — → 0%
    epss
  • 01 SEP 19:58Z
    pypdf: Possible infinite loop for TreeObject.insert_child
    cvelistv5