CVE-2026-41885 Path traversal / URL injection via unsanitised lng/ns/projectId/version in i18next-locize-backend
Attackers can manipulate URL paths in i18next-locize-backend to access or modify unintended resources via unsanitized input parameters.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-41885?
CVE-2026-41885 is a medium-severity path traversal vulnerability in i18next-locize-backend, published on 8 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
i18next-locize-backend is a simple i18next backend for locize.com which can be used in Node.js, in the browser and for Deno. Prior to version 9.0.2, i18next-locize-backend interpolates lng, ns, projectId, and version directly into the configured loadPath / privatePath / addPath / updatePath / getLanguagesPath URL templates with no path-component validation and no encoding. When an application exposes any of these values to user-controlled input (?lng= / ?ns= query parameters via i18next-browser-languagedetector, cookies, request headers, or a URL-derived projectId), a crafted value can change the structure of the outgoing request URL. Affected call sites in lib/index.js (pre-patch): the interpolate() helper is used at the five URL-build sites — _readAny/read (line 415 for private, 426 for public), getLanguages (lines 271 and 296), and writePage (lines 616 and 622) for the missing-key and update POST paths. The helper interpolate in lib/utils.js substitutes raw values with no encoding. This issue has been patched in version 9.0.2.
Which versions are affected by CVE-2026-41885?
2 open source packages ship an affected version, including i18next-locize-backend.
| Package | Affected | Fixed in |
|---|---|---|
i18next-locize-backend npm | All versions | 9.0.2 |
i18next-locize-backend npm | All versions | 9.0.2 |
How do I fix CVE-2026-41885?
Upgrade i18next-locize-backend to 9.0.2 or later.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-41885 being exploited?
There is no known exploitation of CVE-2026-41885 in the wild and no public exploit code.
Sources
Also known as GHSA-mgcp-mfp8-3q45.