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 respon…
Exact source revision recorded 1 Nov 2026 07:10:39 UTC. It does not establish the source's current position. Latest evidence.
euvd · EUVD-2026-28791
Publishedi18next-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.
EUVD source date text has no stated timezone and is retained without inventing a UTC instant. Related bulletin membership is not an alias, common cause or applicability claim. A missing vector with a zero score is treated as unrated. Complete vendor/product and underlying source evidence remains in the original JSON.
Original publisher date fields
datePublished: May 8, 2026, 3:27:05 PM
dateUpdated: May 8, 2026, 11:29:00 PM
- Source published
- May 8, 2026, 3:27:05 PM (timezone not stated)
- Source modified
- May 8, 2026, 11:29:00 PM (timezone not stated)
- Observed here
- 1 Nov 2026 07:10:39 UTC
- Source terms
- ENISA EUVD · source terms and attribution apply
Original source record · Cite this exact observation · Complete original publisher JSON
This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: euvd · ENISA EUVD · source terms and attribution apply. Source text is retained; field grouping and change labels are provided by ChangeIntel.
EUVD CVSS 3.1 · 8.6 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L