{"cve":"CVE-2025-30218","nvd":{"published":"2025-04-02T22:15:19.940","modified":"2026-06-17T09:08:22.653","status":"Analyzed","description":"Next.js is a React framework for building full-stack web applications. To mitigate CVE-2025-29927, Next.js validated the x-middleware-subrequest-id which persisted across multiple incoming requests. However, this subrequest ID is sent to all requests, even if the destination is not the same host as the Next.js application. Initiating a fetch request to a third-party within Middleware will send the x-middleware-subrequest-id to that third party. This vulnerability is fixed in 12.3.6, 13.5.10, 14.2.26, and 15.2.4.","cvss_v4":{"vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U","score":1.7},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N","score":5.9},"cwes":["CWE-200"],"references":["https://github.com/vercel/next.js/security/advisories/GHSA-223j-4rm8-mrmf","https://vercel.com/changelog/cve-2025-30218-5DREmEH765PoeAsrNNQj3O"],"products":["vercel:next.js"],"source":"nvd","synced_at":"2026-10-19T22:00:57.946988208+00:00"},"epss":{"cve":"CVE-2025-30218","score":0.00431,"percentile":0.37411,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-223j-4rm8-mrmf","url":"https://osv.dev/vulnerability/GHSA-223j-4rm8-mrmf","summary":"Next.js may leak x-middleware-subrequest-id to external hosts","modified":"2025-10-13T15:35:50Z","packages":[{"ecosystem":"npm","name":"next","purl":"pkg:npm/next","ranges":[">=12.3.5 <12.3.6"],"fixed":["12.3.6"]},{"ecosystem":"npm","name":"next","purl":"pkg:npm/next","ranges":[">=13.5.9 <13.5.10"],"fixed":["13.5.10"]},{"ecosystem":"npm","name":"next","purl":"pkg:npm/next","ranges":[">=14.2.25 <14.2.26"],"fixed":["14.2.26"]},{"ecosystem":"npm","name":"next","purl":"pkg:npm/next","ranges":[">=15.2.3 <15.2.4"],"fixed":["15.2.4"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}