i18next-fs-backend: Path traversal via unsanitised lng/ns allows arbitrary file read/overwrite_CVE-2026-41693

{
    "lastseen": "",
    "description": "i18next-fs-backend is a backend layer for i18next using in Node.js and for Deno to load translations from the filesystem. Prior to version 2.6.4, i18next-fs-backend substitutes the lng and ns options directly into the configured loadPath / addPath templates and then read / write the resulting file from disk. The interpolation is unencoded and unvalidated, so a crafted lng or ns value \u2014 containing .., a path separator, a control character, a prototype key, or simply an unexpectedly long string \u2014 allows an attacker who can influence either value to read or overwrite files outside the intended locale directory. When lng / ns are derived from untrusted input (request-scoped i18next instances behind an HTTP layer such as i18next-http-middleware, or any framework that lets the end user pick the language via query string, cookie, or header), a single request such as ?lng=../../../../etc/passwd causes the backend to attempt to read that path. This issue has been patched in version 2.6.4.",
    "published": "2026-05-08T15:38:50.525Z",
    "modified": "2026-05-08T15:38:50.525Z",
    "type": "cve",
    "title": "i18next-fs-backend: Path traversal via unsanitised lng/ns allows arbitrary file read/overwrite",
    "source": "GitHub_M",
    "references": "https://github.com/i18next/i18next-fs-backend/security/advisories/GHSA-8847-338w-5hcj",
    "id": "CVE-2026-41693",
    "bulletinFamily": "",
    "cwe": [
        "CWE-73",
        "CWE-22"
    ],
    "cvelist": null,
    "sourceData": "i18next i18next-fs-backend < 2.6.4",
    "sourceHref": "",
    "cvss": {
        "score": 8.2,
        "severity": "HIGH",
        "vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N",
        "version": "3.1"
    },
    "cvss2": [],
    "cvss3": {
        "version": "",
        "vectorString": "",
        "baseScore": 0,
        "baseSeverity": "",
        "attackVector": "",
        "attackComplexity": "",
        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
            "version": "",
            "vectorString": "",
            "baseScore": 0,
            "baseSeverity": "",
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            "privilegesRequired": "",
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            "availabilityImpact": ""
        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "i18next-fs-backend",
    "version": "< 2.6.4",
    "vendor": "i18next",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
    "ai_product": "",
    "ai_version": "",
    "ai_score": 0
}