{"id":"CVE-2026-41683","sourceIdentifier":"security-advisories@github.com","published":"2026-05-08T16:16:11.320","lastModified":"2026-06-17T10:46:59.900","vulnStatus":"Deferred","cveTags":[],"descriptions":[{"lang":"en","value":"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."}],"affected":[{"source":"security-advisories@github.com","affectedData":[{"vendor":"i18next","product":"i18next-http-middleware","versions":[{"version":"< 3.9.3","status":"affected"}]}]}],"metrics":{"cvssMetricV31":[{"source":"security-advisories@github.com","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L","baseScore":8.6,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"LOW","integrityImpact":"HIGH","availabilityImpact":"LOW"},"exploitabilityScore":3.9,"impactScore":4.7}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-05-08T23:28:40.338694Z","id":"CVE-2026-41683","options":[{"exploitation":"none"},{"automatable":"yes"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"weaknesses":[{"source":"security-advisories@github.com","type":"Secondary","description":[{"lang":"en","value":"CWE-79"},{"lang":"en","value":"CWE-113"}]}],"references":[{"url":"https://github.com/i18next/i18next-http-middleware/security/advisories/GHSA-c3h8-g69v-pjrg","source":"security-advisories@github.com"}]}