# 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.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 8 May 2026
- **Updated:** 8 May 2026
- **Also known as:** GHSA-mgcp-mfp8-3q45

## 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.

Weakness: CWE-74 (Improper Neutralization of Special Elements in Output Used by a Downstream Component), CWE-22 (Improper Limitation of a Pathname to a Restricted Directory)

## Which versions are affected by CVE-2026-41885?

2 open source packages ship an affected version, including i18next-locize-backend.


| Package | Ecosystem | 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.

## Is CVE-2026-41885 being exploited?

There is no known exploitation of CVE-2026-41885 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-41885 and fix it if it is affected.

What it is: 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.
Exploitation: There is no known exploitation of CVE-2026-41885 in the wild and no public exploit code.

Affected packages and fixed versions:
- i18next-locize-backend (npm): affected all versions; fixed in 9.0.2
- i18next-locize-backend (npm): affected all versions; fixed in 9.0.2

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-41885/ (Markdown: https://insights.sbomify.com/CVE-2026-41885/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-41885
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-41885
- OSV: https://osv.dev/vulnerability/CVE-2026-41885

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-41885/
Summaries are generated and may contain mistakes; the official description above is the record.