{"id":"CVE-2026-73421","title":"NextAuth.js provides authentication for Next.js","summary":"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.…","severity":"none","cwe":["CWE-285","CWE-636"],"published":"2026-08-13","updated":"2026-09-18","sourceUpdated":"2026-09-18T20:05:53.723","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-73421","references":[{"url":"https://github.com/nextauthjs/next-auth/commit/d008b9b764bf4b322a87e1822d1dda7789258d8f","label":"security-advisories@github.com"},{"url":"https://github.com/nextauthjs/next-auth/releases/tag/next-auth@5.0.0-beta.32","label":"security-advisories@github.com"},{"url":"https://github.com/nextauthjs/next-auth/security/advisories/GHSA-8fpg-xm3f-6cx3","label":"security-advisories@github.com"}],"tags":["nvd"],"epss":0.00643,"epssPercentile":0.48552,"ingestedAt":"2026-09-18T20:51:25.612Z","slug":"CVE-2026-73421","body":"## Overview\n\nNextAuth.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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}