CVE-2026-73418
HighCVSS 7.5Exploitation Probability (EPSS)
Low risk38th percentile - higher than 38% of all known CVEs
Summary
NextAuth.js before @auth/core 0.41.3, next-auth 4.24.15, and 5.0.0-beta.32 can throw an uncaught exception in getToken() when reading a malformed Authorization: Bearer header. When no session cookie is present, getToken() URL-decodes the bearer value before validation, and malformed percent encoding causes decodeURIComponent() to throw. This can lead to per-request denial of service without exposing tokens or bypassing authentication.
Risk Assessment
A single unauthenticated request can trigger an unhandled exception in authentication code, causing temporary unavailability of the application.
Recommendation
Immediately update to @auth/core 0.41.3, next-auth 4.24.15, or 5.0.0-beta.32, which contain the fix.
Original NVD description (English source)
NextAuth.js provides authentication for Next.js. Prior to @auth/core 0.41.3 and next-auth 4.24.15 and 5.0.0-beta.32, the exported getToken() helper in the next-auth/jwt and @auth/core/jwt modules can throw an uncaught exception when it reads a malformed Authorization: Bearer header. When no session cookie is present, getToken() URL-decodes the bearer value before validating it, and malformed percent encoding causes decodeURIComponent() to throw instead of treating the token as invalid. Because getToken() is commonly called in API routes, middleware, and server-side request handlers, a single unauthenticated request can trigger an unhandled exception in code paths that authenticate requests, causing a per-request denial of service without exposing tokens, sessions, or other data and without bypassing authentication. This issue is fixed in @auth/core 0.41.3 and next-auth 4.24.15 and 5.0.0-beta.32.