What is CVE-2026-41683?

CVE-2026-41683 is a high-severity vulnerability in I18next I18next-http-middleware, classified under Cross-site Scripting. CVSS score: 8.6/10. Published 2026-05-08.

How severe is CVE-2026-41683?

High severity. CVSS v3 base score is 8.6 out of 10.

XSS in I18next I18next-http-middleware

CVE-2026-41683

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 respo…

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.000 (4.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.6 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L.

Affected products

I18next I18next-http-middleware — versions < 3.9.3

Weakness classification (CWE)

CWE-79 — Cross-site Scripting
CWE-113 — HTTP Response Splitting

References

security-advisories@github.com (x_refsource_CONFIRM)

Frequently asked questions

What is CVE-2026-41683?: CVE-2026-41683 is a high-severity vulnerability in I18next I18next-http-middleware, classified under Cross-site Scripting. CVSS score: 8.6/10. Published 2026-05-08.
How severe is CVE-2026-41683?: High severity. CVSS v3 base score is 8.6 out of 10.