Unauthorized Access in Next.js Framework Affecting Vercel
CVE-2026-44573

7.5HIGH

Key Information:

Vendor

Vercel
Status
Next.js
Vendor
CVE Published:
13 May 2026

What is CVE-2026-44573?

The Next.js framework, commonly used for building full-stack web applications, contains a vulnerability that affects applications utilizing the Pages Router with internationalization (i18n) settings. In specific configurations, the middleware responsible for authorization checks does not execute for locale-less JSON data requests. Consequently, an attacker can exploit this flaw to access sensitive JSON data for protected pages without fulfilling the necessary authorization requirements. This issue has been rectified in Next.js versions 15.5.16 and 16.2.5.

Affected Version(s)

next.js >= 12.2.0, < 15.5.16 < 12.2.0, 15.5.16

next.js >= 16.0.0, < 16.2.5 < 16.0.0, 16.2.5

References

https://github.com/vercel/next.js/security/advisories/GHS...
x_refsource_CONFIRM

CVSS V3.1

Score:
7.5
Severity:
HIGH
Confidentiality:
High
Integrity:
None
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.