Is CVE-2026-55887 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-55887 being exploited in the wild.

How severe is CVE-2026-55887?

High severity, with a CVSS score of 4, published 15 September 2026.

Which products and versions are affected?

github.com/docker/mcp-gateway (Go) >= 0.21.0, < 0.42.2, SEMVER:introduced=0.21.0,fixed=0.42.2.

Is there a fix for CVE-2026-55887?

Yes. github.com/docker/mcp-gateway (Go): upgrade to 0.42.2 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-55887 attacked?

It is attacked with local access, in a software library.

Am I affected by CVE-2026-55887?

Check whether you run github.com/docker/mcp-gateway (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-55887: Docker MCP Gateway argument injection via OCI image label

Q: Is there a fix for CVE-2026-55887?

Yes. github.com/docker/mcp-gateway (Go): upgrade to 0.42.2 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Q: How is CVE-2026-55887 attacked?

It is attacked with local access, in a software library.

Q: Am I affected by CVE-2026-55887?

Check whether you run github.com/docker/mcp-gateway (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-55887 · Severity: high · CVSS 4 · Published 2026-09-15

Docker MCP Gateway is a tool used to manage Model Context Protocol (MCP) servers. A vulnerability allows a malicious OCI image to inject unauthorized commands when the gateway starts a container. This could allow an attacker to gain full control over the host computer, including the ability to access all files and run programs with administrative privileges.

Vendors: Go.

Quick answers

Is CVE-2026-55887 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-55887 being exploited in the wild.
How severe is CVE-2026-55887?: High severity, with a CVSS score of 4, published 15 September 2026.
Which products and versions are affected?: github.com/docker/mcp-gateway (Go) >= 0.21.0, < 0.42.2, SEMVER:introduced=0.21.0,fixed=0.42.2.
Is there a fix for CVE-2026-55887?: Yes. github.com/docker/mcp-gateway (Go): upgrade to 0.42.2 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-55887 attacked?: It is attacked with local access, in a software library.
Am I affected by CVE-2026-55887?: Check whether you run github.com/docker/mcp-gateway (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

github.com/docker/mcp-gateway (Go): upgrade to 0.42.2 or later
```
go get github.com/docker/mcp-gateway@v0.42.2
```

Technical details

An argument injection vulnerability exists in Docker MCP Gateway due to improper handling of OCI image labels. The 'io.docker.server.metadata' label is unmarshalled directly into a struct containing runtime-shaping fields like Volumes and User. Because these fields are then appended verbatim as flags to a 'docker run' command without validation, an attacker-controlled image can specify flags such as '-v /:/host' or '-u root'. This allows for a complete container escape and arbitrary code execution as root on the host system. The issue is fixed in version 0.42.2 by restricting the parser to only populate descriptive fields.

Affected products

Docker mcp-gateway >= 0.21.0, < 0.42.2

Identifiers

CVE-2026-55887
GHSA-r2xf-7jw5-pjg6
GO-2026-5604

Timeline

2026-06-16: disclosed
2026-06-18: advisory
2026-06-18: patched: Fixed in version 0.42.2

References

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