---
cve: "CVE-2026-84309"
severity: "MEDIUM"
cvss: 6.9
epss: "0.1%"
vendor: "py-pdf"
kev: false
exploited: false
published: "2026-09-01 20:17:25"
tags: [cve, security, medium]
source: tsecurity.de CVE-Dossier
exported: "2026-09-25T12:42:41+02:00"
---

# CVE-2026-84309

> 6.9 MEDIUM · 🧪 PoC

## Beschreibung

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-Vektor

```
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
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Lokal | good |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |

## Patch verfügbar (OSV)

- c9ba557d565d57c53a0b3a0be06c0a4c29b0559b (Commit)
- 2b60c99973df8d7f959cd46658604d881be3de3a (Commit)

## Referenzen

- <https://github.com/py-pdf/pypdf/security/advisories/GHSA-jp53-mhqp-8xcg>
- <https://github.com/py-pdf/pypdf/pull/3964>
- <https://github.com/py-pdf/pypdf/commit/c9ba557d565d57c53a0b3a0be06c0a4c29b0559b>
- <https://github.com/py-pdf/pypdf/releases/tag/6.16.0>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-84309) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_