Invoking failure to reject ASCII-only Punycode-encoded labels in golang.org/x/net/idna_MS:CVE-2026-39821

{
    "lastseen": "2026-05-29T09:14:58",
    "description": "",
    "published": "2026-05-27T08:03:52",
    "modified": "2026-05-28T21:45:32",
    "type": "mscve",
    "title": "Invoking failure to reject ASCII-only Punycode-encoded labels in golang.org/x/net/idna",
    "source": "",
    "references": "",
    "id": "MS:CVE-2026-39821",
    "bulletinFamily": "microsoft",
    "cwe": null,
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    "cvss": {
        "score": 10,
        "severity": "CRITICAL",
        "vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N/E:U",
        "version": "3.1"
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    "href": "https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2026-39821",
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