CVE-2025-30218

Summary

Next.js is a React framework for building full-stack web applications. To mitigate CVE-2025-29927, Next.js validated the x-middleware-subrequest-id which persisted across multiple incoming requests. However, this subrequest ID is sent to all requests, even if the destination is not the same host as the Next.js application. Initiating a fetch request to a third-party within Middleware will send the x-middleware-subrequest-id to that third party. This vulnerability is fixed in 12.3.6, 13.5.10, 14.2.26, and 15.2.4.

Affected Software

VendorProductVersion RangeStatus
vercelnext.js= 12.3.5affected
vercelnext.js= 13.5.9affected
vercelnext.js= 14.2.25affected
vercelnext.js= 15.2.3affected

Weaknesses

  • CWE-200: CWE-200: Exposure of Sensitive Information to an Unauthorized Actor

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

References