Comodo Internet Security Inspect.sys IPv6 Integer Underflow Remote Denial of Service_CVE-2026-49494

{
    "lastseen": "",
    "description": "Comodo Internet Security's firewall driver Inspect.sys contains an integer underflow in its IPv6 packet parser. The parser decrements an unsigned 64-bit payload-length value (taken from the IPv6 fixed header's payload length field) by the size of each IPv6 extension header without validating it, so a packet whose declared payload length is smaller than the sum of its extension-header lengths underflows the value to a near-maximal 64-bit integer. Because IPv6 parsing occurs before firewall rule enforcement, a remote, unauthenticated attacker can send a single crafted IPv6 packet - even to a host with all ports blocked - to trigger an out-of-bounds read (and, on a separate code path, an oversized memcpy) in the Windows kernel at DISPATCH_LEVEL, crashing the system (BSOD).",
    "published": "2026-06-07T12:08:59.492Z",
    "modified": "2026-06-07T12:08:59.492Z",
    "type": "cve",
    "title": "Comodo Internet Security Inspect.sys IPv6 Integer Underflow Remote Denial of Service",
    "source": "VulnCheck",
    "references": "https://malwaretech.com/2026/06/exploiting-a-remote-kernel-vulnerability-in-comodo-internet-security.html\nhttps://github.com/MalwareTech/ComoDoS\nhttps://www.vulncheck.com/advisories/comodo-internet-security-inspect-sys-ipv6-integer-underflow-remote-denial-of-service",
    "id": "CVE-2026-49494",
    "bulletinFamily": "",
    "cwe": [
        "CWE-191"
    ],
    "cvelist": null,
    "sourceData": "Comodo Comodo Internet Security 0",
    "sourceHref": "",
    "cvss": {
        "score": 8.7,
        "severity": "HIGH",
        "vector": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
        "version": "4.0"
    },
    "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": "Comodo Internet Security",
    "version": "0",
    "vendor": "Comodo",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
    "ai_product": "",
    "ai_version": "",
    "ai_score": 0
}