CVE-2026-42306 Moby: Race condition in docker cp allows bind mount redirection to host path
A race condition in Docker cp allows malicious containers to redirect bind mounts, potentially overwriting host files or causing denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-42306?
CVE-2026-42306 is a high-severity vulnerability in moby, published on 12 Jun 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official 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.
Which versions are affected by CVE-2026-42306?
9 open source packages ship an affected version, including github.com/moby/moby, github.com/docker/docker and github.com/moby/moby/v2. It affects 3 products.
| Package | Affected | Fixed in |
|---|---|---|
github.com/moby/moby Go | All versions | None |
github.com/moby/moby Go | All versions to 28.5.2 | None |
github.com/moby/moby Go | All versions to 28.5.2 | None |
github.com/docker/docker Go | All versions | None |
github.com/docker/docker Go | All versions to 28.5.2 | None |
github.com/docker/docker Go | All versions to 28.5.2 | None |
3 more packages
github.com/moby/moby/v2 Go | All versions | 2.0.0-beta.14 |
github.com/moby/moby/v2 Go | All versions | 2.0.0-beta.14 |
github.com/moby/moby/v2 Go | All versions | 2.0.0-beta.14 |
Products include Docker Engine, Mobyproject Moby, Mobyproject Moby\/V2.
How do I fix CVE-2026-42306?
Upgrade to a fixed version.
Is CVE-2026-42306 being exploited?
There is no known exploitation of CVE-2026-42306 in the wild and no public exploit code.
Other vulnerabilities in moby
Sources
Also known as BELL-CVE-2026-42306, CLEANSTART-2026-FX37210, DEBIAN-CVE-2026-42306, ECHO-4e5e-0474-bde5, GHSA-rg2x-37c3-w2rh, GO-2026-5617 and 264 more.