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CVE-2026-41683GHSA-C3H8-G69V-PJRG

HTTP response splitting and DoS in i18next-http-middleware via unsanitised Content-Language header

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 3.9.3
None on Exploit-DB, Metasploit or GitHub
  • Exploitation: none
  • Automatable: yes
  • Technical impact: partial

Summary

i18next-http-middleware is a middleware to be used with Node.js web frameworks like express or Fastify and also for Deno. Prior to version 3.9.3, i18next-http-middleware wrote user-controlled language values into the Content-Language response header after passing them through utils.escape(), which is an HTML-entity encoder that does not strip carriage return, line feed, or other control characters. When the application used an older i18next (< 19.5.0) that still exercised the backward-compatibility fallback at LanguageDetector.js:100 or otherwise produced a raw detected value, CRLF sequences in the attacker-controlled lng parameter reached res.setHeader('Content-Language', ...) verbatim. This issue has been patched in version 3.9.3.

Timeline

  1. CVE published
  2. CISA SSVC assessment

    Exploitation: none · Automatable: yes · Technical impact: partial

  3. Record last updated

Affected versions

  • i18next i18next-http-middleware

    fixed in 3.9.3

  • i18next-http-middlewarenpm

    fixed in 3.9.3

References 1

GitHub · i18next/i18next-http-middleware