Bug 2507690

Summary:	CVE-2026-42306 docker-buildx: Moby container framework: Host file overwrite via race condition in docker cp mount setup [fedora-all]
Product:	[Fedora] Fedora	Reporter:	Matteo Signorini <msignori>
Component:	docker-buildx	Assignee:	Maxwell G <maxwell>
Status:	CLOSED NOTABUG	QA Contact:
Severity:	high	Docs Contact:
Priority:	high
Version:	rawhide	CC:	bradley.g.smith, go-sig, maxwell
Target Milestone:	---	Keywords:	Security, SecurityTracking
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:	{"flaws": ["93171e02-3645-4f6c-ad7c-68f121520a10"]}
Fixed In Version:		Doc Type:	---
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2026-08-04 16:37:28 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:
Bug Blocks:	2488484

Description Matteo Signorini 2026-07-27 20:45:10 UTC

Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

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.

Comment 1 Brad Smith 2026-08-04 16:37:28 UTC

    {
      "vulnerability": {
        "@id": "https://pkg.go.dev/vuln/GO-2026-5617",
        "name": "GO-2026-5617",
        "description": "Race condition in 'docker cp' in github.com/docker/docker allows bind m
ount redirection",
        "aliases": [
          "CVE-2026-42306",
          "GHSA-rg2x-37c3-w2rh"
        ]
      },
      "products": [
        {
          "@id": "Unknown Product",
          "subcomponents": [
            {
              "@id": "pkg:golang/github.com%2Fdocker%2Fdocker.2+incompatible"
            }
          ]
        }
      ],
      "status": "not_affected",
      "justification": "vulnerable_code_not_present",
      "impact_statement": "Govulncheck determined that the vulnerable code isn't called"
    },