CVE-2026-48689_CVE-2026-48689

{
    "lastseen": "",
    "description": "FastNetMon Community Edition through 1.2.9 contains an off-by-one heap-based buffer overflow in the dynamic_binary_buffer_t class (src/dynamic_binary_buffer.hpp). Five methods (append_dynamic_buffer, append_data_as_pointer, append_data_as_object_ptr, memcpy_from_ptr, memcpy_from_object_ptr) use an incorrect bounds check of the form 'if (offset + length > maximum_internal_storage_size + 1)' instead of the correct 'if (offset + length > maximum_internal_storage_size)'. This allows writing exactly one byte past the end of the heap-allocated buffer. The class is used pervasively in BGP message encoding/decoding, NetFlow template processing, and Flow Spec NLRI construction. An attacker who can send network traffic (NetFlow, sFlow, IPFIX, or BGP) to a FastNetMon instance can trigger this overflow, potentially achieving arbitrary code execution by corrupting heap metadata. Notably, the append_byte() method uses the correct bounds check, confirming the inconsistency.",
    "published": "2026-05-26T00:00:00.000Z",
    "modified": "2026-05-27T00:20:18.668Z",
    "type": "cve",
    "title": "CVE-2026-48689",
    "source": "mitre",
    "references": "https://github.com/pavel-odintsov/fastnetmon\nhttps://github.com/pavel-odintsov/fastnetmon/blob/master/src/dynamic_binary_buffer.hpp\nhttps://lorikeetsecurity.com/blog/fastnetmon-cve-2026-48689-dynamic-buffer-off-by-one",
    "id": "CVE-2026-48689",
    "bulletinFamily": "",
    "cwe": [
        "CWE-193",
        "CWE-122"
    ],
    "cvelist": null,
    "sourceData": "n/a n/a n/a",
    "sourceHref": "",
    "cvss": {
        "score": 9.8,
        "severity": "CRITICAL",
        "vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
        "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": "FastNetMon Community Edition",
    "version": "1.2.9",
    "vendor": "FastNetMon",
    "ai_description": "Off-by-one heap-based buffer overflow in the dynamic_binary_buffer_t class, allowing arbitrary code execution by corrupting heap metadata",
    "ai_severity": "Critical",
    "ai_vendor": "FastNetMon",
    "ai_product": "FastNetMon Community Edition",
    "ai_version": "1.2.9",
    "ai_score": 9.8
}