{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "3.9.3"
              }
            ],
            "source": "AFFECTED_FIELD"
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "c6624343818c63e9877ba98125f7451580eae618"
            }
          ],
          "repo": "https://github.com/i18next/i18next-http-middleware",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-c3h8-g69v-pjrg"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-113",
      "CWE-79"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/41xxx/CVE-2026-41683.json"
  },
  "details": "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 (\u003c 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.",
  "id": "CVE-2026-41683",
  "modified": "2026-07-08T05:36:46.828055649Z",
  "published": "2026-05-08T15:27:05.036Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/41xxx/CVE-2026-41683.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/i18next/i18next-http-middleware/security/advisories/GHSA-c3h8-g69v-pjrg"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-41683"
    }
  ],
  "schema_version": "1.7.5",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L",
      "type": "CVSS_V3"
    }
  ],
  "summary": "HTTP response splitting and DoS in i18next-http-middleware via unsanitised Content-Language header"
}