Parse Server: Stored XSS via trailing-dot filename bypassing file upload extension blocklist_CVE-2026-53724

{
    "lastseen": "",
    "description": "Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 8.6.79 and 9.9.1-alpha.4, the default file upload extension blocklist can be bypassed by appending a trailing dot to a filename whose extension would otherwise be blocked (e.g. poc.svg.). The trailing dot causes the extension parser to extract an empty string, which short-circuits the blocklist check, and the attacker-controlled Content-Type is forwarded to the storage adapter unchanged. Storage adapters that persist and serve the provided Content-Type (such as S3 or GCS) then serve the file with an active type such as image/svg+xml, enabling stored XSS when a victim opens the file URL. The default GridFS adapter is not affected because it sets X-Content-Type-Options: nosniff on responses. This issue has been patched in versions 8.6.79 and 9.9.1-alpha.4.",
    "published": "2026-06-12T18:34:38.237Z",
    "modified": "2026-06-12T18:34:38.237Z",
    "type": "cve",
    "title": "Parse Server: Stored XSS via trailing-dot filename bypassing file upload extension blocklist",
    "source": "GitHub_M",
    "references": "https://github.com/parse-community/parse-server/security/advisories/GHSA-7wqv-xjf3-x35v\nhttps://github.com/parse-community/parse-server/pull/10489\nhttps://github.com/parse-community/parse-server/pull/10490",
    "id": "CVE-2026-53724",
    "bulletinFamily": "",
    "cwe": [
        "CWE-434",
        "CWE-79"
    ],
    "cvelist": null,
    "sourceData": "parse-community parse-server < 8.6.79\nparse-community parse-server >= 9.0.0, < 9.9.1-alpha.4",
    "sourceHref": "",
    "cvss": {
        "score": 2.1,
        "severity": "LOW",
        "vector": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:N/VI:L/VA:N/SC:L/SI:L/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": "< 8.6.79",
    "vendor": "parse-community",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
    "ai_product": "",
    "ai_version": "",
    "ai_score": 0
}