{"cve":"CVE-2026-44573","nvd":{"published":"2026-05-13T17:16:22.627","modified":"2026-10-26T17:10:03.270","status":"Modified","description":"Next.js is a React framework for building full-stack web applications. From 12.2.0 to before 15.5.16 and 16.2.5, Applications using the Pages Router with i18n configured and middleware/proxy-based authorization can allow unauthorized access to protected page data through locale-less /_next/data/<buildId>/<page>.json requests. In affected configurations, middleware does not run for the unprefixed data route, allowing an attacker to retrieve SSR JSON for protected pages without passing the intended authorization checks. This vulnerability is fixed in 15.5.16 and 16.2.5.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","score":7.5},"cwes":["CWE-863","CWE-551"],"references":["https://github.com/vercel/next.js/security/advisories/GHSA-36qx-fr4f-26g5","https://access.redhat.com/errata/RHSA-2026:34608","https://access.redhat.com/errata/RHSA-2026:37272","https://access.redhat.com/errata/RHSA-2026:40974","https://access.redhat.com/errata/RHSA-2026:54435"],"products":["vercel:next.js"],"source":"nvd","synced_at":"2026-10-26T17:39:09.812804557+00:00"},"epss":{"cve":"CVE-2026-44573","score":0.00796,"percentile":0.56205,"date":"2026-10-26"},"kev":null,"osv":[{"id":"GHSA-36qx-fr4f-26g5","url":"https://osv.dev/vulnerability/GHSA-36qx-fr4f-26g5","summary":"Next.js has a Middleware / Proxy bypass in Pages Router applications using i18n","modified":"2026-09-10T03:51:04.325298044Z","packages":[{"ecosystem":"npm","name":"next","purl":"pkg:npm/next","ranges":[">=12.2.0 <15.5.16"],"fixed":["15.5.16"]},{"ecosystem":"npm","name":"next","purl":"pkg:npm/next","ranges":[">=16.0.0 <16.2.5"],"fixed":["16.2.5"]}]}],"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."]}