Server-side Request Forgery (SSRF) Affecting i18next-http-backend package, versions <4.0.2
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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- published8 Oct 2026
- disclosed6 Oct 2026
- creditUnknown
Introduced: 6 Oct 2026
NewCVE-2026-105800 (opens in a new tab)How to fix?
Upgrade i18next-http-backend to version 4.0.2 or higher.
Overview
i18next-http-backend is an i18next-http-backend is a backend layer for i18next using in Node.js, in the browser and for Deno.
Affected versions of this package are vulnerable to Server-side Request Forgery (SSRF) via insufficient validation in isSafeUrlSegment functions in lib/utils.js, where user-controlled lng or ns values are interpolated into loadPath/addPath URL templates without rejecting scheme-bearing strings. When a template begins directly with a placeholder (e.g. {{lng}}/{{ns}}.json with no leading origin or path), an attacker can supply a lng value such as http:127.0.0.1:8080 to cause the HTTP backend to issue a request to an arbitrary absolute URL, or an ns value of //evil.example/x to produce a protocol-relative URL in browsers, redirecting requests outside the intended origin.
Note: This is only exploitable when the loadPath or addPath template begins directly with a placeholder, with no leading origin or path segment. The default /locales/{{lng}}/{{ns}}.json template and any template with a leading path or origin are not affected.