SSRF in I18next I18next-Http-Backend
CVE-2026-105800
i18next-http-backend is a backend layer for i18next that loads translation resources in Node.js, browsers, and Deno. Prior to 4.0.2, attacker-controlled language or namespace values interpolated into a custom loadPath or addPath that begins directly with {{lng}} or {{ns}} can make colon-based input become an absolute URL or, in browsers, make a double-slash namespace become a protocol-relative URL. The resulting request can leave the intended origin and cause URL injection or server-side request forgery. The default /locales/{{lng}}/{{ns}}.json template and templates with a leading path or origin are not affected because the placeholder does not occupy the URL's structural beginning. This issue is fixed in version 4.0.2.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 3.7 (Low). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
- I18next I18next-Http-Backend — versions < 4.0.2
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-105800?
- CVE-2026-105800 is a low-severity vulnerability in I18next I18next-Http-Backend, classified under Improper Neutralization of Special Elements in Output Used by a Downstream Component (Injection). CVSS score: 3.7/10. Published 2026-10-06.
- How severe is CVE-2026-105800?
- Low severity. CVSS v3 base score is 3.7 out of 10.