CVE-2026-44575

Summary

Next.js is a React framework for building full-stack web applications. From 15.2.0 to before 15.5.16 and 16.2.5, App Router applications that rely on middleware or proxy-based checks for authorization can allow unauthorized access through transport-specific route variants used for segment prefetching. In affected configurations, specially crafted .rsc and segment-prefetch URLs can resolve to the same page without being matched by the intended middleware rule, which can allow protected content to be reached without the expected authorization check. This vulnerability is fixed in 15.5.16 and 16.2.5.

Affected Software

VendorProductVersion RangeStatus
vercelnext.js>= 16.0.0, < 16.2.5affected
vercelnext.js>= 15.2.0, < 15.5.16affected

Weaknesses

  • CWE-288: CWE-288: Authentication Bypass Using an Alternate Path or Channel

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: yes
    • Technical Impact: partial

next.js: Next.js: Unauthorized access to protected content via middleware bypass

Additional References

References