---
cve: "CVE-2026-59950"
severity: "HIGH"
cvss: 7.6
epss: "0.2%"
vendor: "modelcontextprotocol"
kev: false
exploited: false
published: "2026-07-15 21:16:55"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-21T14:47:52+02:00"
---

# CVE-2026-59950

> 7.6 HIGH · 🧪 PoC

## Beschreibung

The MCP Python SDK, called mcp on PyPI, is a Python implementation of the Model Context Protocol (MCP). Prior to 1.28.1, the deprecated mcp.server.websocket.websocket_server transport accepted WebSocket handshakes without applying Host or Origin header validation, leaving no SDK-level way to restrict which origins could connect to applications that exposed that transport. This issue is fixed in version 1.28.1.

## CVSS-Vektor

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

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

## Patch verfügbar (OSV)

- 777b8d06710c140e3606b0d4598e2aa48546c266 (Commit)

## Referenzen

- <https://github.com/modelcontextprotocol/python-sdk/security/advisories/GHSA-vj7q-gjh5-988w>
- <https://github.com/modelcontextprotocol/python-sdk/pull/2992>
- <https://github.com/modelcontextprotocol/python-sdk/commit/777b8d06710c140e3606b0d4598e2aa48546c266>
- <https://github.com/modelcontextprotocol/python-sdk/releases/tag/v1.28.1>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-59950) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_