Parse Server: Pre-authentication denial of service via client version header regex backtracking_CVE-2026-47138

{
    "lastseen": "",
    "description": "Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 8.6.77 and 9.9.1-alpha.1, an unauthenticated attacker who knows a publicly-known Parse Application ID can submit a single HTTP request whose client SDK version field contains adversarial input that triggers polynomial backtracking in a request-header parser. The parsing runs before session authentication and before rate limiting on every /parse/* request, so the request consumes seconds to minutes of synchronous CPU on a Node.js worker before any access control evaluates it. A small number of concurrent requests can saturate a worker; a single large request via the body-field variant can pin a worker for minutes. Production deployments running the default configuration are affected. This issue has been patched in versions 8.6.77 and 9.9.1-alpha.1.",
    "published": "2026-06-12T18:22:02.751Z",
    "modified": "2026-06-12T18:56:14.419Z",
    "type": "cve",
    "title": "Parse Server: Pre-authentication denial of service via client version header regex backtracking",
    "source": "GitHub_M",
    "references": "https://github.com/parse-community/parse-server/security/advisories/GHSA-38m6-82c8-4xfm\nhttps://github.com/parse-community/parse-server/pull/10463\nhttps://github.com/parse-community/parse-server/pull/10464",
    "id": "CVE-2026-47138",
    "bulletinFamily": "",
    "cwe": [
        "CWE-1333"
    ],
    "cvelist": null,
    "sourceData": "parse-community parse-server < 8.6.77\nparse-community parse-server >= 9.0.0, < 9.9.1-alpha.1",
    "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": "parse-server",
    "version": "< 8.6.77",
    "vendor": "parse-community",
    "ai_description": "Pre-authentication denial of service via client version header regex backtracking",
    "ai_severity": "High",
    "ai_vendor": "Parse Community",
    "ai_product": "Parse Server",
    "ai_version": "< 8.6.77, >= 9.0.0, < 9.9.1-alpha.1",
    "ai_score": 8.7
}