VulnerabilityAnalyzed

CVE-2026-40155

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.

MEDIUM 5.4EPSS 0.21%

Does this matter?

Lower severity and a low EPSS score (0.21%). Track it; it rarely justifies an emergency change on its own.

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 3.1: 5.4 MEDIUMCVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:L/A:N
EPSS: 0.21% probability · 12th percentile
CISA KEV: Not listed
Weakness: CWE-362, CWE-863
Affected: auth0/nextjs-auth0
Source: security-advisories@github.com

References

https://github.com/auth0/nextjs-auth0/commit/98c36dc306970c2230ea1a32efef431d29b99978Patch
https://github.com/auth0/nextjs-auth0/releases/tag/v4.18.0Product, Release Notes
https://github.com/auth0/nextjs-auth0/security/advisories/GHSA-xq8m-7c5p-c2r6Vendor Advisory

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.