{"id":"CVE-2026-40299","state":"PUBLISHED","title":"next-intl has an open redirect vulnerability","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`.","publishedAt":"2026-04-17T20:49:05.642Z","updatedAt":"2026-04-20T15:58:51.149Z","severity":{"score":6.9,"label":"Medium","version":"4.0","vector":"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","source":"GitHub_M"},"assigner":"GitHub_M","products":["amannn next-intl"],"affected":[{"vendor":"amannn","product":"next-intl","versions":[{"version":"< 4.9.1","status":"affected"}]}],"references":["https://github.com/amannn/next-intl/security/advisories/GHSA-8f24-v5vv-gm5j","https://github.com/amannn/next-intl/pull/2304","https://github.com/amannn/next-intl/commit/1c80b668aa6d853f470319eec10a3f61e78a70e6","https://github.com/amannn/next-intl/releases/tag/v4.9.1"],"weaknesses":["CWE-601"],"ingestedAt":"2026-10-29T20:11:57.932Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/40xxx/CVE-2026-40299.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-40299","state":"PUBLISHED","datePublished":"2026-04-17T20:49:05.642Z","dateUpdated":"2026-04-20T15:58:51.149Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-04-10T20:22:44.035Z"},"containers":{"cna":{"title":"next-intl has an open redirect vulnerability","descriptions":[{"lang":"en","value":"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`."}],"affected":[{"vendor":"amannn","product":"next-intl","versions":[{"version":"< 4.9.1","status":"affected"}]}],"references":[{"url":"https://github.com/amannn/next-intl/security/advisories/GHSA-8f24-v5vv-gm5j","name":"https://github.com/amannn/next-intl/security/advisories/GHSA-8f24-v5vv-gm5j","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/amannn/next-intl/pull/2304","name":"https://github.com/amannn/next-intl/pull/2304","tags":["x_refsource_MISC"]},{"url":"https://github.com/amannn/next-intl/commit/1c80b668aa6d853f470319eec10a3f61e78a70e6","name":"https://github.com/amannn/next-intl/commit/1c80b668aa6d853f470319eec10a3f61e78a70e6","tags":["x_refsource_MISC"]},{"url":"https://github.com/amannn/next-intl/releases/tag/v4.9.1","name":"https://github.com/amannn/next-intl/releases/tag/v4.9.1","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"LOW","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":6.9,"baseSeverity":"MEDIUM","vectorString":"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","version":"4.0"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-601","lang":"en","description":"CWE-601: URL Redirection to Untrusted Site ('Open Redirect')","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-04-17T20:49:05.642Z"},"source":{"advisory":"GHSA-8f24-v5vv-gm5j","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-04-20T15:56:01.407919Z","id":"CVE-2026-40299","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-04-20T15:58:51.149Z"}}]}}}