Fireshare has Path Traversal Arbitrary File Write in `/api/uploadChunked`_CVE-2026-33645

{
    "lastseen": "",
    "description": "Fireshare facilitates self-hosted media and link sharing. In version 1.5.1, an authenticated path traversal vulnerability in Fireshare\u2019s chunked upload endpoint allows an attacker to write arbitrary files outside the intended upload directory. The `checkSum` multipart field is used directly in filesystem path construction without sanitization or containment checks. This enables unauthorized file writes to attacker-chosen paths writable by the Fireshare process (e.g., container `/tmp`), violating integrity and potentially enabling follow-on attacks depending on deployment. Version 1.5.2 fixes the issue.",
    "published": "2026-03-26T20:58:21.521Z",
    "modified": "2026-03-27T20:01:09.752Z",
    "type": "cve",
    "title": "Fireshare has Path Traversal Arbitrary File Write in `/api/uploadChunked`",
    "source": "GitHub_M",
    "references": "https://github.com/ShaneIsrael/fireshare/security/advisories/GHSA-7q8r-vpq3-89m7\nhttps://github.com/ShaneIsrael/fireshare/releases/tag/v1.5.2",
    "id": "CVE-2026-33645",
    "bulletinFamily": "",
    "cwe": [
        "CWE-22",
        "CWE-73"
    ],
    "cvelist": null,
    "sourceData": "ShaneIsrael fireshare = 1.5.2",
    "sourceHref": "",
    "cvss": {
        "score": 7.1,
        "severity": "HIGH",
        "vector": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L",
        "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": "fireshare",
    "version": "= 1.5.2",
    "vendor": "ShaneIsrael",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
    "ai_product": "",
    "ai_version": "",
    "ai_score": 0
}