CVE-2026-40155: CWE-863: Incorrect Authorization in auth0 nextjs-auth0
CVE-2026-40155 is an authorization vulnerability in the Auth0 Next. js SDK versions 4. 12. 0 through 4. 17. 1. It affects projects using the proxy handler endpoints /me/* and /my-org/* with DPoP enabled. The issue arises when simultaneous requests trigger a nonce retry, causing improper token request result lookups by the proxy cache fetcher. This vulnerability has been fixed in version 4. 18.
AI Analysis
Technical Summary
The Auth0 Next.js SDK, used for user authentication in Next.js applications, contains an incorrect authorization vulnerability (CWE-863) in versions 4.12.0 to 4.17.1. When simultaneous requests cause a nonce retry, the proxy cache fetcher may perform improper lookups for token request results, potentially leading to unauthorized access. This affects projects that use both the vulnerable SDK versions and the proxy handler endpoints /me/* and /my-org/* with DPoP enabled. The issue was resolved in version 4.18.0.
Potential Impact
If exploited, this vulnerability could allow unauthorized access to user-specific or organization-specific data due to improper authorization checks during token request processing. The impact is primarily confidentiality loss (high), with limited integrity impact and no availability impact as per the CVSS vector. No known exploits are reported in the wild.
Mitigation Recommendations
Upgrade to Auth0 Next.js SDK version 4.18.0 or later, where this issue is fixed. Since this is a library vulnerability, applying the official patch by updating the SDK version is the recommended remediation. No additional vendor advisory content is available, so patch status is confirmed by the version fix information.
CVE-2026-40155: CWE-863: Incorrect Authorization in auth0 nextjs-auth0
Description
CVE-2026-40155 is an authorization vulnerability in the Auth0 Next. js SDK versions 4. 12. 0 through 4. 17. 1. It affects projects using the proxy handler endpoints /me/* and /my-org/* with DPoP enabled. The issue arises when simultaneous requests trigger a nonce retry, causing improper token request result lookups by the proxy cache fetcher. This vulnerability has been fixed in version 4. 18.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The Auth0 Next.js SDK, used for user authentication in Next.js applications, contains an incorrect authorization vulnerability (CWE-863) in versions 4.12.0 to 4.17.1. When simultaneous requests cause a nonce retry, the proxy cache fetcher may perform improper lookups for token request results, potentially leading to unauthorized access. This affects projects that use both the vulnerable SDK versions and the proxy handler endpoints /me/* and /my-org/* with DPoP enabled. The issue was resolved in version 4.18.0.
Potential Impact
If exploited, this vulnerability could allow unauthorized access to user-specific or organization-specific data due to improper authorization checks during token request processing. The impact is primarily confidentiality loss (high), with limited integrity impact and no availability impact as per the CVSS vector. No known exploits are reported in the wild.
Mitigation Recommendations
Upgrade to Auth0 Next.js SDK version 4.18.0 or later, where this issue is fixed. Since this is a library vulnerability, applying the official patch by updating the SDK version is the recommended remediation. No additional vendor advisory content is available, so patch status is confirmed by the version fix information.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-04-09T19:31:56.013Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 69e2a136bdfbbecc59908353
Added to database: 4/17/2026, 9:08:06 PM
Last enriched: 4/17/2026, 9:23:33 PM
Last updated: 4/18/2026, 5:19:16 AM
Views: 8
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