Nmap – Integer Underflow in IPv6 Extension Header Parsing_CVE-2026-58058

{
    "lastseen": "",
    "description": "Nmap through 7.99 does not keep the IPv6 extension-header walk within the captured packet in ipv6_get_data_primitive (libnetutil/netutil.cc), so the pointer advances past the buffer and the remaining-length computation underflows to a large value. A scanned target or on-path attacker returning a crafted IPv6 response with a truncated extension header can trigger out-of-bounds reads and a crash during raw IPv6 scans.",
    "published": "2026-06-28T01:32:59.336Z",
    "modified": "2026-06-28T01:32:59.336Z",
    "type": "cve",
    "title": "Nmap - Integer Underflow in IPv6 Extension Header Parsing",
    "source": "VulnCheck",
    "references": "https://github.com/bikini/exploitarium/tree/main/nmap-ipv6-extlen-wrap-poc\nhttps://github.com/nmap/nmap/commit/bb6754e76bb1686315008e1aa1c40202a513fb83\nhttps://nmap.org/changelog.html\nhttps://www.vulncheck.com/advisories/nmap-integer-underflow-in-ipv6-extension-header-parsing",
    "id": "CVE-2026-58058",
    "bulletinFamily": "",
    "cwe": [
        "CWE-191"
    ],
    "cvelist": null,
    "sourceData": "Nmap Nmap 0",
    "sourceHref": "",
    "cvss": {
        "score": 6.5,
        "severity": "MEDIUM",
        "vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L",
        "version": "3.1"
    },
    "cvss2": [],
    "cvss3": {
        "version": "",
        "vectorString": "",
        "baseScore": 0,
        "baseSeverity": "",
        "attackVector": "",
        "attackComplexity": "",
        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
            "version": "",
            "vectorString": "",
            "baseScore": 0,
            "baseSeverity": "",
            "attackVector": "",
            "attackComplexity": "",
            "privilegesRequired": "",
            "userInteraction": "",
            "scope": "",
            "confidentialityImpact": "",
            "integrityImpact": "",
            "availabilityImpact": ""
        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "Nmap",
    "version": "0",
    "vendor": "Nmap",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
    "ai_product": "",
    "ai_version": "",
    "ai_score": 0
}