# i18next-http-middleware has path traversal / SSRF via user-controlled language and namespace parameters

Advisory record · `GHSA-jfgf-83c5-2c4m`

- **Identifiers:** `GHSA-jfgf-83c5-2c4m` · `CVE-2026-42353`
- **State:** Confirmed
- **Severity:** CVSS 8.2 High
- **Critical:** No
- **Weakness (CWE):** [CWE-22](https://cwe.mitre.org/data/definitions/22.html) · [CWE-918](https://cwe.mitre.org/data/definitions/918.html)
- **Tags:** [Path traversal](https://agentprime.io/advisories/tag/path-traversal.md) · [Server-side request forgery (SSRF)](https://agentprime.io/advisories/tag/ssrf.md)
- **Published:** 29 Apr 2026
- **Updated:** 13 May 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 29 Apr 2026, 22:26 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `i18next-http-middleware` (npm): affected `<3.9.3`; fixed in `3.9.3`

## Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

## Severity and exploitation

- 8.2 High, CVSS 3.1: `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N`, from CNA (GitHub_M)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0039, the 33rd percentile, on 14 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

This record came from the full history of the GitHub Advisory Database, published 29 Apr 2026. New records show when each source confirmed them.

## Sources

- [GitHub Advisory Database: GHSA-jfgf-83c5-2c4m](https://github.com/advisories/GHSA-jfgf-83c5-2c4m)
- [OSV: GHSA-jfgf-83c5-2c4m](https://osv.dev/vulnerability/GHSA-jfgf-83c5-2c4m)
- <https://github.com/i18next/i18next-http-middleware/security/advisories/GHSA-jfgf-83c5-2c4m>
- <https://nvd.nist.gov/vuln/detail/CVE-2026-42353>
- <https://github.com/i18next/i18next-http-middleware>
- <https://www.i18next.com/how-to/faq#how-should-the-language-codes-be-formatted>

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.

## Check whether this affects you

A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: <https://agentprime.io/mcp.md>
- In a browser: <https://agentprime.io/check/> reads your lockfile in the browser, never uploading it.
- Whether it touches your code, with file and line: the Claude Code plugin, <https://agentprime.io/plugin.md>
- As JSON: <https://api.agentprime.io/v1/advisories/GHSA-jfgf-83c5-2c4m>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

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The web page: <https://agentprime.io/advisories/GHSA-jfgf-83c5-2c4m/>. Everything for agents: <https://agentprime.io/llms.txt>.