CVE-2026-55887: MCP Gateway: Argument injection via OCI image label YAML in Docker MCP Gateway
Description
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.
CWE-88
Tracked companies
Mapped from the CVE’s affected-product data, NVD CPE matches, vendor advisories or package feeds. A mapping means the vendor’s software is named, not that its hosted service was exposed.
Status incidents that name it
No tracked status incident names this CVE.
Affected vendors and products
docker: mcp-gateway
References
- CVE record on cve.org (opens in new tab)
- NVD entry (opens in new tab)
- github.com/docker/mcp-gateway/commit/306d2d94a3b526f43281313321bf784f2d46a7fe (opens in new tab)
- github.com/docker/mcp-gateway/commit/439b2200d9e26a4ff414aeb043785df45a78422b (opens in new tab)
- github.com/docker/mcp-gateway/pull/498 (opens in new tab)
- github.com/docker/mcp-gateway/releases/tag/v0.42.2 (opens in new tab)
- github.com/docker/mcp-gateway/security/advisories/GHSA-r2xf-7jw5-pjg6 (opens in new tab)
- CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (opens in new tab)
- This product uses data from the NVD API but is not endorsed or certified by the NVD. (opens in new tab)
- Known Exploited Vulnerabilities catalog from CISA. (opens in new tab)
- EPSS scores from FIRST (Exploit Prediction Scoring System). (opens in new tab)