5.4

CVE-2026-40155: auth0 nextjs-auth0 Race Condition

CVSS: 5.4v3.1MediumAnalyzed
AliasesGHSA-xq8m-7c5p-c2r6
Published 17-04-2026Last modified 20-04-2026
Open JSON

Vulnerability summary

CVE-2026-40155 is a medium (CVSS 5.4) Race Condition vulnerability in auth0 nextjs-auth0. EPSS estimates a 0.26% chance of exploitation in the next 30 days, higher than 17% of scored vulnerabilities.

Overall risk
22/100
0100
Low · default modelHow is this calculated?
CVSS score
5.4/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.26%
0%100%
Low · +0.05 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 17-04-2026
    PublishedVulnerability first disclosed.
  2. 20-04-2026
    Last modifiedVulnerability information updated.

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 metrics

3 scores · 3 sources · 1 version

EPSS trend

Probability

0.26%

Chance of exploitation in the next 30 days

Percentile

17%

Versus all other CVEs

30-day change

+0.05 pp

From 0.21% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.26%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

@auth01 product
  • nextjs-auth0≥ 4.12.0, < 4.18.0
Auth01 product

2 vendors · 2 products

References

5 links