{"cve":"CVE-2026-73421","nvd":{"published":"2026-08-13T22:17:26.447","modified":"2026-09-18T20:05:53.723","status":"Awaiting Analysis","description":"NextAuth.js provides authentication for Next.js. From next-auth 5.0.0-beta.0 until 5.0.0-beta.32, applications that gate access by checking only for the existence of the auth object returned by the auth() wrapper can fail open when Auth.js has a server configuration error. In middleware, Route Handlers, React Server Components, and other auth() entry points, a non-OK session response is parsed into a truthy error object instead of null, so checks such as !!auth and if (req.auth) evaluate to true for unauthenticated requests. A provider missing both the issuer and authorization endpoint triggers InvalidEndpoints, and an unset AUTH_SECRET or another server configuration error can produce the same behavior. There is no impact while configuration is valid, but after a deployment becomes misconfigured, routes protected only by session existence silently grant access to every visitor. This issue is fixed in next-auth 5.0.0-beta.32.","cvss_v4":{"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N","score":9.1},"cvss_v3":null,"cwes":["CWE-285","CWE-636"],"references":["https://github.com/nextauthjs/next-auth/commit/d008b9b764bf4b322a87e1822d1dda7789258d8f","https://github.com/nextauthjs/next-auth/releases/tag/next-auth@5.0.0-beta.32","https://github.com/nextauthjs/next-auth/security/advisories/GHSA-8fpg-xm3f-6cx3"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:48:17.459049833+00:00"},"epss":{"cve":"CVE-2026-73421","score":0.00643,"percentile":0.50826,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-8fpg-xm3f-6cx3","url":"https://osv.dev/vulnerability/GHSA-8fpg-xm3f-6cx3","summary":"Auth.js: Configuration errors can cause existence-based auth checks to fail open (auth object populated with an error)","modified":"2026-08-12T20:56:01.891204Z","packages":[{"ecosystem":"npm","name":"next-auth","purl":"pkg:npm/next-auth","ranges":[">=5.0.0-beta.0 <5.0.0-beta.32"],"fixed":["5.0.0-beta.32"]}]}],"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."]}