multer vulnerable to Denial of Service via deeply nested field names_CVE-2026-5079

{
    "lastseen": "",
    "description": "Impact: multer versions 1.0.0 through 2.1.1 and 3.0.0-alpha.1 are vulnerable to a Denial of Service via deeply nested field names in multipart form data. The append-field dependency parses bracket notation in field names with no limit on nesting depth, allowing an attacker to force allocation of deeply nested object structures that consume CPU and memory. A single HTTP request with a crafted multipart body is sufficient to exploit this.\n\nPatches: Users should upgrade to multer 2.2.0 (2.x line) or 3.0.0-alpha.2 (3.x prerelease) and configure the new limits.fieldNestingDepth option to the minimum depth their application requires.\n\nWorkarounds: Set limits.fields to a reasonable value to reduce the number of fields an attacker can send per request. This does not fully mitigate the issue but limits the impact.",
    "published": "2026-06-15T13:56:45.520Z",
    "modified": "2026-06-15T13:56:45.520Z",
    "type": "cve",
    "title": "multer vulnerable to Denial of Service via deeply nested field names",
    "source": "openjs",
    "references": "https://github.com/expressjs/multer/security/advisories/GHSA-72gw-mp4g-v24j\nhttps://cna.openjsf.org/security-advisories.html",
    "id": "CVE-2026-5079",
    "bulletinFamily": "",
    "cwe": [
        "CWE-400"
    ],
    "cvelist": null,
    "sourceData": "multer multer 1.0.0\nmulter multer 3.0.0-alpha.1",
    "sourceHref": "",
    "cvss": {
        "score": 7.5,
        "severity": "HIGH",
        "vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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": "",
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            "availabilityImpact": ""
        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "multer",
    "version": "1.0.0",
    "vendor": "multer",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
    "ai_product": "",
    "ai_version": "",
    "ai_score": 0
}