---
cve: "CVE-2026-55887"
severity: "HIGH"
cvss: 8.7
epss: "0.2%"
vendor: "Docker"
kev: false
exploited: false
published: "2026-09-15 16:17:16"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-22T01:44:48+02:00"
---

# CVE-2026-55887

> 8.7 HIGH · 🧪 PoC

## Beschreibung

MCP Gateway allows easy and secure running and deployment of MCP servers. From 0.21.0 until 0.42.2, Docker MCP Gateway YAML-unmarshalled the attacker-controlled io.docker.server.metadata OCI image label into the broad catalog.Server structure for direct docker:// references and catalog snapshot imports in pkg/oci/self_contained.go and pkg/workingset/workingset.go. Runtime-shaping fields including Volumes, User, and ExtraHosts were then appended to the docker run argument vector without an origin allowlist, allowing a malicious image author to request host filesystem or Docker socket mounts and UID 0 execution when a victim selected or pulled the image. This container-creation-time boundary bypass can execute arbitrary code on the host and is not prevented by no-new-privileges because no in-container privilege escalation is required. This issue is fixed in version 0.42.2.

## CVSS-Vektor

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

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

## Patch verfügbar (OSV)

- 306d2d94a3b526f43281313321bf784f2d46a7fe (Commit)
- 439b2200d9e26a4ff414aeb043785df45a78422b (Commit)

## Referenzen

- <https://github.com/docker/mcp-gateway/security/advisories/GHSA-r2xf-7jw5-pjg6>
- <https://github.com/docker/mcp-gateway/pull/498>
- <https://github.com/docker/mcp-gateway/commit/306d2d94a3b526f43281313321bf784f2d46a7fe>
- <https://github.com/docker/mcp-gateway/commit/439b2200d9e26a4ff414aeb043785df45a78422b>
- <https://github.com/docker/mcp-gateway/releases/tag/v0.42.2>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-55887) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_