CVE-2026-56857

{"id": "CVE-2026-56857", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-56857", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "yes"}, {"technicalImpact": "total"}], "version": "2.0.3", "timestamp": "2026-10-09T15:35:58.663117Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "cvssData": {"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"}, "impactScore": 5.9, "exploitabilityScore": 3.9}]}, "affected": [{"source": "security@golang.org", "affectedData": [{"vendor": "Go standard library", "product": "os", "versions": [{"status": "affected", "version": "0", "lessThan": "1.26.9", "versionType": "semver"}, {"status": "affected", "version": "1.27.0-0", "lessThan": "1.27.2", "versionType": "semver"}], "platforms": ["windows"], "packageName": "os", "collectionURL": "https://pkg.go.dev", "defaultStatus": "unaffected", "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", "product": "internal/syscall/windows", "versions": [{"status": "affected", "version": "0", "lessThan": "1.26.9", "versionType": "semver"}, {"status": "affected", "version": "1.27.0-0", "lessThan": "1.27.2", "versionType": "semver"}], "platforms": ["windows"], "packageName": "internal/syscall/windows", "collectionURL": "https://pkg.go.dev", "defaultStatus": "unaffected", "programRoutines": [{"name": "Mkdirat"}]}]}], "published": "2026-10-08T23:17:01.487", "references": [{"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", "source": "security@golang.org"}], "vulnStatus": "Awaiting Analysis", "weaknesses": [{"type": "Secondary", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "description": [{"lang": "en", "value": "CWE-1386"}]}], "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)."}], "lastModified": "2026-10-09T16:35:35.900", "sourceIdentifier": "security@golang.org"}