---
cve: "CVE-2026-48529"
severity: "MEDIUM"
cvss: 6.0
epss: "14%"
vendor: "GitHub"
kev: false
exploited: false
published: "2026-06-26 17:16:33"
tags: [cve, security, medium]
source: tsecurity.de CVE-Dossier
exported: "2026-09-13T17:38:53+02:00"
---

# CVE-2026-48529

> 6.0 MEDIUM · 🧪 PoC

## Beschreibung

GitHub MCP Server is GitHub's official MCP Server. From 0.22.0 until 1.1.2, when running in HTTP mode with --lockdown-mode enabled, the RepoAccessCache is implemented as a process-global singleton initialized with the first authenticated user's GraphQL client. All subsequent requests from different users share this singleton and their lockdown-related GraphQL queries are executed using the first user's credentials. The singleton is never updated to reflect later users' tokens. This vulnerability is fixed in 1.1.2.

## CVSS-Vektor

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

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

## Patch verfügbar (OSV)

- b5397f6e3305531a1c534b90b2d347a70fa84da9 (Commit)

## Referenzen

- <https://github.com/github/github-mcp-server/security/advisories/GHSA-pjp5-fpmr-3349>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-48529) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_