5.4
MEDIUM CVSS 3.1
CVE-2026-40155
Auth0 Next.js SDK has Improper Proxy Cache Lookup
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.

INFO

Published Date :

April 17, 2026, 9:16 p.m.

Last Modified :

April 17, 2026, 9:16 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-40155 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 MEDIUM [email protected]
Solution
Update Auth0 Next.js SDK to version 4.18.0 or later to fix the authentication issue.
  • Update the Auth0 Next.js SDK to version 4.18.0 or later.
  • Verify the SDK version in your project.
  • Ensure DPoP is configured correctly if used.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-40155.

URL Resource
https://github.com/auth0/nextjs-auth0/commit/98c36dc306970c2230ea1a32efef431d29b99978
https://github.com/auth0/nextjs-auth0/releases/tag/v4.18.0
https://github.com/auth0/nextjs-auth0/security/advisories/GHSA-xq8m-7c5p-c2r6
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-40155 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-40155 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-40155 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-40155 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Apr. 17, 2026

    Action Type Old Value New Value
    Added 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.
    Added CVSS V3.1 AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:L/A:N
    Added CWE CWE-362
    Added CWE CWE-863
    Added Reference https://github.com/auth0/nextjs-auth0/commit/98c36dc306970c2230ea1a32efef431d29b99978
    Added Reference https://github.com/auth0/nextjs-auth0/releases/tag/v4.18.0
    Added Reference https://github.com/auth0/nextjs-auth0/security/advisories/GHSA-xq8m-7c5p-c2r6
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.