{"id":"CVE-2026-41683","revision":"b93027607d9748ed8075e4209de86352","records":[{"revision":"b93027607d9748ed8075e4209de86352","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-41683","aliases":[],"title":"HTTP response splitting and DoS in i18next-http-middleware via unsanitised Content-Language header","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.","state":0,"publishedAt":"2026-05-08T15:27:05.036+00:00","modifiedAt":"2026-05-08T23:29:00.23+00:00","affected":[{"ecosystem":"Vendor product","name":"i18next-http-middleware","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"i18next\",\n                    \"product\": \"i18next-http-middleware\",\n                    \"versions\": [\n                        {\n                            \"version\": \"< 3.9.3\",\n                            \"status\": \"affected\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 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,"severity":"HIGH"}],"references":["https://github.com/i18next/i18next-http-middleware/security/advisories/GHSA-c3h8-g69v-pjrg"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-41683","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-41683","identifiers":["CVE-2026-41683"]},"retained":false,"historicalAffected":[]}],"coverage":[]}