---
cve: "CVE-2026-77220"
severity: "HIGH"
cvss: 7.1
epss: "28.1%"
vendor: "michaelrsweet"
kev: false
exploited: false
published: "2026-08-21 21:17:06"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-08-31T07:54:49+02:00"
---

# CVE-2026-77220

> 7.1 HIGH · 🧪 PoC

## Beschreibung

PDFio before 1.6.5 contains a dangling pointer vulnerability in the dictionary string-formatting function that stores a pointer to a stack-local buffer in the document dictionary without copying the string value. In multi-threaded or pooled-request environments, attackers or concurrent users can trigger stack memory reuse across requests, causing cross-tenant document content corruption by silently overwriting one caller's dictionary string values with another caller's data.

## CVSS-Vektor

```
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
```

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

## Patch verfügbar (OSV)

- 5102eddff28d9b605f3e6783d50ad380f61f692e (Commit)
- 22b9afc800c5833f9e851e35938972bd4c76a357 (Commit)

## Referenzen

- <https://github.com/michaelrsweet/pdfio/releases/tag/v1.6.5>
- <https://github.com/michaelrsweet/pdfio/commit/22b9afc800c5833f9e851e35938972bd4c76a357>
- <https://www.vulncheck.com/advisories/pdfio-dangling-pointer-via-dictionary-string-formatting>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-77220) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_