CVE-2026-558878.7HighCWE-88

CVE-2026-55887: MCP Gateway: Argument injection via OCI image label YAML in Docker MCP Gateway

docker · mcp-gateway

Affected: docker mcp-gateway · Exploitation: unlikely (under 1%)

Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.

0.2%probability of exploitation in the next 30 days

12th percentile

050100

Higher than 12% of scored CVEs

8.7HighCVSS 4.0

LowMediumHighCrit.

DescriptionCVE.org

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.

Affected products1

From the CVE record. A product or version that is not listed is unknown, not unaffected.

docker · mcp-gateway>= 0.21.0, < 0.42.2

On the Atlas

Every published CVE is on the CyberSIXT Atlas, grouped by weakness, vendor and month.

Open the Atlas

Exploitation: Unlikely (under 1%). EPSS under 1%, or no score yet.
CISA KEV: Not listed
Public check: No public nuclei template
Weakness: Improper Neutralization of Argument Delimiters in a Command · Command and Code Injection
Vendor: docker
Published: September 2026
Band: Unlikely (under 1%), September 2026

CoverageNo articles yet

No CyberSIXT article names CVE-2026-55887 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.