CVE-2026-41691
Description
Copilot said: i18nextify is a JavaScript library that adds i18nextify is a JavaScript library that adds website internationalization via a script tag, without source code changes. Versions prior to 3.0.5 interpolate the lng and ns values directly into the configured loadPath / addPath URL template without any encoding, validation, or path sanitisation. When an application exposes the language-code selection to user-controlled input (the default — i18next-browser-languagedetector reads ?lng= query params, cookies, localStorage, and request headers), an attacker can inject characters that change the structure of the outgoing request URL. This is a single URL-injection vulnerability. The attacker-controlled value is neutralised before it is used as part of an output URL string; the attack shape covers both path traversal and broader URL-structure injection — both are closed by the one interpolateUrl sanitisation fix. This issue has been fixed in version 3.0.5. If users cannot upgrade immediately, they can work around the issue by sanitising lng / ns before they reach i18next (strip .., /, \, ?, #, %, whitespace, and control characters; cap the length).
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
Package impact
| Ecosystem | Package | Vulnerable | Fixed |
|---|---|---|---|
| npm | i18next-http-backend | <3.0.5 | 3.0.5 |
| NPM | i18next-http-backend | < 3.0.5 | 3.0.5 |
Application impact
| Vendor | Product | Versions | Fixed |
|---|---|---|---|
| i18next | i18next-http-backend | {"endExcluding":"3.0.5"} | 3.0.5 |
References
- https://github.com/i18next/i18next-http-backend/commit/4cee84f229c637b9c182366d3156f726d407a621
- https://github.com/i18next/i18next-http-backend/security/advisories/GHSA-q89c-q3h5-w34g
- https://nvd.nist.gov/vuln/detail/CVE-2026-41691
- https://github.com/i18next/i18next-http-backend
- https://github.com/advisories/GHSA-q89c-q3h5-w34g
CWEs
CWE-22 CWE-74
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.