FKIE_CVE-2026-56857

Vulnerability from fkie_nvd - Published: 2026-10-08 23:17 - Updated: 2026-10-08 23:17
Severity
Summary
On Windows, when the target of Root.Mkdir or Root.MkdirAll is a junction pointing to an empty location, the operation can create a directory at the junction target even when that target is located outside the root. This only applies to operations where the last path component is a junction (path/to/junction, but not path/junction/target).
References
security@golang.orghttps://go.dev/cl/847305
security@golang.orghttps://go.dev/issue/81739
security@golang.orghttps://groups.google.com/g/golang-announce/c/U2fTuyDJznI
security@golang.orghttps://pkg.go.dev/vuln/GO-2026-6604
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "collectionURL": "https://pkg.go.dev",
          "defaultStatus": "unaffected",
          "packageName": "os",
          "platforms": [
            "windows"
          ],
          "product": "os",
          "programRoutines": [
            {
              "name": "Root.Mkdir"
            },
            {
              "name": "doInRoot"
            },
            {
              "name": "rootMkdirAll"
            },
            {
              "name": "Root.Chmod"
            },
            {
              "name": "Root.Chown"
            },
            {
              "name": "Root.Chtimes"
            },
            {
              "name": "Root.Lchown"
            },
            {
              "name": "Root.Link"
            },
            {
              "name": "Root.MkdirAll"
            },
            {
              "name": "Root.Remove"
            },
            {
              "name": "Root.RemoveAll"
            },
            {
              "name": "Root.Rename"
            },
            {
              "name": "Root.Symlink"
            }
          ],
          "vendor": "Go standard library",
          "versions": [
            {
              "lessThan": "1.26.9",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThan": "1.27.2",
              "status": "affected",
              "version": "1.27.0-0",
              "versionType": "semver"
            }
          ]
        },
        {
          "collectionURL": "https://pkg.go.dev",
          "defaultStatus": "unaffected",
          "packageName": "internal/syscall/windows",
          "platforms": [
            "windows"
          ],
          "product": "internal/syscall/windows",
          "programRoutines": [
            {
              "name": "Mkdirat"
            }
          ],
          "vendor": "Go standard library",
          "versions": [
            {
              "lessThan": "1.26.9",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThan": "1.27.2",
              "status": "affected",
              "version": "1.27.0-0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "source": "security@golang.org"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "On Windows, when the target of Root.Mkdir or Root.MkdirAll is a junction pointing to an empty location, the operation can create a directory at the junction target even when that target is located outside the root. This only applies to operations where the last path component is a junction (path/to/junction, but not path/junction/target)."
    }
  ],
  "id": "CVE-2026-56857",
  "lastModified": "2026-10-08T23:17:01.487",
  "metrics": {},
  "published": "2026-10-08T23:17:01.487",
  "references": [
    {
      "source": "security@golang.org",
      "url": "https://go.dev/cl/847305"
    },
    {
      "source": "security@golang.org",
      "url": "https://go.dev/issue/81739"
    },
    {
      "source": "security@golang.org",
      "url": "https://groups.google.com/g/golang-announce/c/U2fTuyDJznI"
    },
    {
      "source": "security@golang.org",
      "url": "https://pkg.go.dev/vuln/GO-2026-6604"
    }
  ],
  "sourceIdentifier": "security@golang.org",
  "vulnStatus": "Received"
}



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