{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-56857",
        "assignerOrgId": "1bb62c36-49e3-4200-9d77-64a1400537cc",
        "state": "PUBLISHED",
        "assignerShortName": "Go",
        "dateReserved": "2026-06-23T15:10:49.353Z",
        "datePublished": "2026-10-08T22:53:58.387Z",
        "dateUpdated": "2026-10-09T15:36:01.712Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "1bb62c36-49e3-4200-9d77-64a1400537cc",
                "shortName": "Go",
                "dateUpdated": "2026-10-08T22:53:58.387Z"
            },
            "title": "Root.Mkdir(All) can follow junctions out of the root on Windows in os",
            "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)."
                }
            ],
            "affected": [
                {
                    "vendor": "Go standard library",
                    "product": "os",
                    "collectionURL": "https://pkg.go.dev",
                    "packageName": "os",
                    "versions": [
                        {
                            "version": "0",
                            "lessThan": "1.26.9",
                            "status": "affected",
                            "versionType": "semver"
                        },
                        {
                            "version": "1.27.0-0",
                            "lessThan": "1.27.2",
                            "status": "affected",
                            "versionType": "semver"
                        }
                    ],
                    "platforms": [
                        "windows"
                    ],
                    "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"
                        }
                    ],
                    "defaultStatus": "unaffected"
                },
                {
                    "vendor": "Go standard library",
                    "product": "internal/syscall/windows",
                    "collectionURL": "https://pkg.go.dev",
                    "packageName": "internal/syscall/windows",
                    "versions": [
                        {
                            "version": "0",
                            "lessThan": "1.26.9",
                            "status": "affected",
                            "versionType": "semver"
                        },
                        {
                            "version": "1.27.0-0",
                            "lessThan": "1.27.2",
                            "status": "affected",
                            "versionType": "semver"
                        }
                    ],
                    "platforms": [
                        "windows"
                    ],
                    "programRoutines": [
                        {
                            "name": "Mkdirat"
                        }
                    ],
                    "defaultStatus": "unaffected"
                }
            ],
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "lang": "en",
                            "description": "CWE-1386: Insecure Operation on Windows Junction / Mount Point"
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://go.dev/cl/847305"
                },
                {
                    "url": "https://go.dev/issue/81739"
                },
                {
                    "url": "https://groups.google.com/g/golang-announce/c/U2fTuyDJznI"
                },
                {
                    "url": "https://pkg.go.dev/vuln/GO-2026-6604"
                }
            ],
            "credits": [
                {
                    "lang": "en",
                    "value": "Daniele Ballarini"
                }
            ]
        },
        "adp": [
            {
                "problemTypes": [
                    {
                        "descriptions": [
                            {
                                "type": "CWE",
                                "cweId": "CWE-1386",
                                "lang": "en",
                                "description": "CWE-1386 Insecure Operation on Windows Junction / Mount Point"
                            }
                        ]
                    }
                ],
                "metrics": [
                    {
                        "cvssV3_1": {
                            "scope": "UNCHANGED",
                            "version": "3.1",
                            "baseScore": 9.8,
                            "attackVector": "NETWORK",
                            "baseSeverity": "CRITICAL",
                            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
                            "integrityImpact": "HIGH",
                            "userInteraction": "NONE",
                            "attackComplexity": "LOW",
                            "availabilityImpact": "HIGH",
                            "privilegesRequired": "NONE",
                            "confidentialityImpact": "HIGH"
                        }
                    },
                    {
                        "other": {
                            "type": "ssvc",
                            "content": {
                                "timestamp": "2026-10-09T15:35:58.663117Z",
                                "id": "CVE-2026-56857",
                                "options": [
                                    {
                                        "Exploitation": "none"
                                    },
                                    {
                                        "Automatable": "yes"
                                    },
                                    {
                                        "Technical Impact": "total"
                                    }
                                ],
                                "role": "CISA Coordinator",
                                "version": "2.0.3"
                            }
                        }
                    }
                ],
                "title": "CISA ADP Vulnrichment",
                "providerMetadata": {
                    "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
                    "shortName": "CISA-ADP",
                    "dateUpdated": "2026-10-09T15:36:01.712Z"
                }
            }
        ]
    }
}