{"cve":"CVE-2026-41683","nvd":{"published":"2026-05-08T16:16:11.320","modified":"2026-10-26T18:10:00.173","status":"Deferred","description":"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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L","score":8.6},"cwes":["CWE-79","CWE-113"],"references":["https://github.com/i18next/i18next-http-middleware/security/advisories/GHSA-c3h8-g69v-pjrg"],"products":[],"source":"nvd","synced_at":"2026-10-26T18:27:13.530666824+00:00"},"epss":{"cve":"CVE-2026-41683","score":0.00327,"percentile":0.25632,"date":"2026-10-26"},"kev":null,"osv":[{"id":"GHSA-c3h8-g69v-pjrg","url":"https://osv.dev/vulnerability/GHSA-c3h8-g69v-pjrg","summary":"i18next-http-middleware: HTTP response splitting and DoS via unsanitised Content-Language header","modified":"2026-05-13T13:52:05.255318Z","packages":[{"ecosystem":"npm","name":"i18next-http-middleware","purl":"pkg:npm/i18next-http-middleware","ranges":["<3.9.3"],"fixed":["3.9.3"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}