CVE-2026-40155 MEDIUM

CVE-2026-40155: Auth0 Next.js SDK has Improper Proxy Cache Lookup

Vendor Auth0
Product nextjs-auth0
Weakness CWE-863 · Incorrect authorization
Published April 17, 2026
Last update April 20, 2026

CVSS base score

5.4/10
Attack vector Network
Attack complexity High
Privileges required Low
User interaction Required
Confidentiality High
Integrity Low

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:L/A:N

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

April 17, 2026 CVE published
April 20, 2026 Record updated