---
id: "CVE-2026-115730"
kind: "vulnerability"
aliases: ["CVE-2026-115730"]
title: "i18next-http-backend: namespace slash redirects translation loads to attacker hosts"
severity: "low"
cvss: 3.1
epss: 0.00356
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["frontend", "i18next", "javascript", "node", "package"]
not_affected_if: ["no-user-input-in-loadpath", "static-namespaces"]
published_at: "2026-10-23T13:17:08+00:00"
first_seen_at: "2026-10-23T21:57:33+00:00"
updated_at: "2026-10-25T12:38:50+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-115730", "first_seen_at": "2026-10-23T21:57:33+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2026-115730", "first_seen_at": "2026-10-25T12:38:50+00:00"}]
---

# i18next-http-backend: namespace slash redirects translation loads to attacker hosts

i18next-http-backend 4.0.2 has an incomplete fix in interpolateUrl(): a namespace value starting with a slash turns the translation URL into a protocol-relative URL. An attacker who controls the namespace can load translations from an attacker-hosted server, which can inject UI content and cross-site scripting.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the installed version with `npm ls i18next-http-backend`
- Look for `loadPath` or `addPath` templates that interpolate a user-controlled namespace value

## Timeline

- 2026-10-23T21:57:33+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-115730
- 2026-10-25T12:38:50+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2026-115730

## From the sources

i18next-http-backend 4.0.2 contains an incomplete fix in interpolateUrl() that allows attackers to redirect translation requests by supplying an ns value starting with a slash. Attackers controlling the namespace value can form a protocol-relative URL in loadPath or addPath templates to load attacker-hosted translations, enabling UI content injection and cross-site scripting.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_