CVE-2026-40299

next-intl provides internationalization for Next.js. Applications using the next-intl middleware prior to version 4.9.1with localePrefix: 'as-needed' could construct URLs where path handling and the WHATWG URL parser resolved a relative redirect target to another host e.g. scheme-relative // or...

Open Redirect

Overview next-intl is an Internationalization i18n for Next.js Affected versions of this package are vulnerable to Open Redirect in the middleware process when localePrefix is set to 'as-needed'. An attacker can redirect users to an external site by crafting URLs that exploit the way relative...

GHSA-8F24-V5VV-GM5J next-intl has an open redirect vulnerability

Impact Applications using the next-intl middleware with localePrefix: 'as-needed' could construct URLs where path handling and the WHATWG URL parser resolved a relative redirect target to another host e.g. scheme-relative // or control characters stripped by the URL parser, so the middleware coul...