MessagePack-CSharp: Denial of service vulnerabilities can swamp the CPU or crash the process with stack and heap overflows_CVE-2026-48502

{
    "lastseen": "",
    "description": "MessagePack for C# is a MessagePack serializer for C#. Prior to 2.5.301 and 3.1.7, MessagePackReader.ReadDateTime() can allocate stack memory based on an attacker-controlled MessagePack extension length. In the slow path for timestamp extension parsing, the computed tokenSize includes the extension body length from the wire and is used in a stackalloc operation before the extension length is validated as one of the valid timestamp sizes. A very small payload can claim a large timestamp extension body and cause a stack allocation large enough to trigger an uncatchable StackOverflowException, terminating the host process. This vulnerability is fixed in 2.5.301 and 3.1.7.",
    "published": "2026-06-22T21:18:29.190Z",
    "modified": "2026-06-22T21:18:29.190Z",
    "type": "cve",
    "title": "MessagePack-CSharp: Denial of service vulnerabilities can swamp the CPU or crash the process with stack and heap overflows",
    "source": "GitHub_M",
    "references": "https://github.com/MessagePack-CSharp/MessagePack-CSharp/security/advisories/GHSA-382j-8mxh-c7x2",
    "id": "CVE-2026-48502",
    "bulletinFamily": "",
    "cwe": [
        "CWE-125",
        "CWE-190",
        "CWE-407",
        "CWE-409",
        "CWE-470",
        "CWE-502",
        "CWE-674",
        "CWE-789",
        "CWE-1188"
    ],
    "cvelist": null,
    "sourceData": "MessagePack-CSharp MessagePack-CSharp >= 3.1.7, < 3.1.7\nMessagePack-CSharp MessagePack-CSharp < 2.5.301",
    "sourceHref": "",
    "cvss": {
        "score": 8.2,
        "severity": "HIGH",
        "vector": "CVSS:4.0/AV:N/AC:H/AT:P/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": "",
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            "baseScore": 0,
            "baseSeverity": "",
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        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "MessagePack-CSharp",
    "version": ">= 3.1.7, < 3.1.7",
    "vendor": "MessagePack-CSharp",
    "ai_description": "",
    "ai_severity": "",
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    "ai_score": 0
}