Skip to content

Improper Proxy Cache Lookup in the Auth0 Next.js SDK

Moderate
jennyyang-okta published GHSA-xq8m-7c5p-c2r6 Apr 17, 2026

Package

npm @auth0/nextjs-auth0 (npm)

Affected versions

>=4.12.0 and <=4.17.0

Patched versions

4.18.0

Description

Description

In affected versions of the Next.js SDK, simultaneous requests that trigger a nonce retry may cause the proxy cache fetcher to perform improper lookups for the token request results.

Am I Affected?

You are affected if you meet all of the following preconditions:

  • Applications using the auth0/nextjs-auth0 SDK, versions 4.12.0 to 4.17.0, and
  • Applications using the proxy handler /me/* and /my-org/* with DPoP enabled.

Affected product and versions

Auth0/nextjs-auth0 v4.12.0 to 4.17.0

Resolution

Upgrade Auth0/nextjs-auth0 version to v4.18.0 or greater

Acknowledgements

Okta would like to thank Reynaldo Immanuel for their discovery and responsible disclosure.

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
High
Privileges required
Low
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
Low
Availability
None

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:L/A:N

CVE ID

CVE-2026-40155

Weaknesses

Incorrect Authorization

The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check. Learn more on MITRE.