CVE-2026-40299 | BDVDB-2026-327573 Detail

Description#

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 control characters stripped by the URL parser), so the middleware could redirect the browser off-site while the user still started from a trusted app URL. The problem has been patchedin `next-intl@4.9.1`.

Impact#

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Exploit#

History#

1. Version 12026-04-17Record published in the CVE List.
2. Version 22026-04-20Most recent update recorded in the CVE List.