CVE-2026-40299
MEDIUM EPSS 25.8%
Published Apr 17, 20262mo ago · Modified Jun 17, 20261w ago
6.9 CVSS 4.0
Published Apr 17, 2026 2mo ago
Last Modified Jun 17, 2026 1w ago
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`.
CVSS Details
Base Score
Exploitability
Impact
Vector string
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope X
Threat Intelligence
EPSS Exploit Probability
25.8% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available
Weaknesses 1
CWE-601
References 4
- github.com https://github.com/amannn/next-intl/commit/1c80b668aa6d853f470319eec10a3f61e78a70e6
- github.com https://github.com/amannn/next-intl/pull/2304
- github.com https://github.com/amannn/next-intl/releases/tag/v4.9.1
- github.com https://github.com/amannn/next-intl/security/advisories/GHSA-8f24-v5vv-gm5j
Remediation
No remediation data recorded yet
Check vendor advisories and the NVD entry for patch availability.