---
cve: "CVE-2026-59724"
severity: "HIGH"
cvss: 7.5
epss: "34%"
vendor: "socketio"
kev: false
exploited: false
published: "2026-07-08 16:16:32"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-18T21:58:06+02:00"
---

# CVE-2026-59724

> 7.5 HIGH · 🧪 PoC

## Beschreibung

Socket.IO enables bidirectional and low-latency communication for every platform. From 6.5.0 before 6.6.7, Engine.IO servers with WebTransport enabled can resolve a crafted session ID such as __proto__ through an inherited property of the clients object during WebTransport upgrade handling, causing a TypeError and denial of service. This issue is fixed in version 6.6.7.

## CVSS-Vektor

```
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |
| S Scope | Unverändert | good |
| C Vertraulichkeit | Keine | good |
| I Integrität | Keine | good |
| A Verfügbarkeit | Hoch | bad |

## Patch verfügbar (OSV)

- 439a8f669c6788b512dd76011c4476830d67515b (Commit)
- 1fa1f46cd420ac5b57bb4c04c959b58f3c79158c (Commit)

## Referenzen

- <https://github.com/socketio/socket.io/security/advisories/GHSA-gr94-w7qr-f4j3>
- <https://github.com/socketio/socket.io/commit/1fa1f46cd420ac5b57bb4c04c959b58f3c79158c>
- <https://github.com/socketio/socket.io/releases/tag/engine.io@6.6.7>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-59724) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_