CVE-2026-42306
HIGHCVE-2026-42306 is a high-severity (CVSS 7.2) CWE-61 vulnerability in github.com/docker/docker. O3 Security confirms whether CVE-2026-42306 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Moby: Race condition in docker cp allows bind mount redirection to host path
Real-World Exposure
github.com/docker/docker🐹github.com/moby/moby/v2🐹github.com/moby/mobyReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/docker/docker | all versions | No fix |
| 🐹Go | github.com/moby/moby/v2 | all versions | 2.0.0-beta.14 |
| 🐹Go | github.com/moby/moby | all versions | No fix |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/docker/docker. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
No patched version of github.com/docker/docker has shipped for CVE-2026-42306 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-42306 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-42306. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-42306 in your dependencies?
O3 detects CVE-2026-42306 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.