{"id":"CVE-2026-41693","aliases":["GHSA-8847-338w-5hcj"],"url":"https://o3.security/vulnerability/CVE-2026-41693","summary":"i18next-fs-backend: Path traversal via unsanitised lng/ns allows arbitrary file read/overwrite","details":"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 — containing .., a path separator, a control character, a prototype key, or simply an unexpectedly long string — 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":"2026-08-07T11:31:21.981493428Z","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"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"npm","name":"i18next-fs-backend","fixedVersion":"2.6.4"}],"fix":null,"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/41xxx/CVE-2026-41693.json"},{"type":"ADVISORY","url":"https://github.com/i18next/i18next-fs-backend/security/advisories/GHSA-8847-338w-5hcj"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-41693"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-07T11:31:21.981493428Z"}}