Vulnerability Description
The Auth0 Next.js SDK is a library for implementing user authentication in Next.js applications. In versions 4.12.0 through 4.17.1, simultaneous requests that trigger a nonce retry may cause the proxy cache fetcher to perform improper lookups for the token request results. Users are affected if their project uses both the vulnerable versions and the proxy handler /me/* and /my-org/* with DPoP enabled. This issue has been fixed in version 4.18.0.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Auth0 | Nextjs-Auth0 | >= 4.12.0, < 4.18.0 |
Related Weaknesses (CWE)
References
- https://github.com/auth0/nextjs-auth0/commit/98c36dc306970c2230ea1a32efef431d29bPatch
- https://github.com/auth0/nextjs-auth0/releases/tag/v4.18.0ProductRelease Notes
- https://github.com/auth0/nextjs-auth0/security/advisories/GHSA-xq8m-7c5p-c2r6Vendor Advisory
FAQ
What is CVE-2026-40155?
CVE-2026-40155 is a vulnerability with a CVSS score of 5.4 (MEDIUM). The Auth0 Next.js SDK is a library for implementing user authentication in Next.js applications. In versions 4.12.0 through 4.17.1, simultaneous requests that trigger a nonce retry may cause the proxy...
How severe is CVE-2026-40155?
CVE-2026-40155 has been rated MEDIUM with a CVSS base score of 5.4/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-40155?
Check the references section above for vendor advisories and patch information. Affected products include: Auth0 Nextjs-Auth0.