CVE-2026-64647

Summary

Next.js is a React framework for building full-stack web applications. In versions 12.0.0 through 15.5.20 and 16.0.0 through 16.2.10, a server-side fetch with a request body may return a cached response body from a different request to the same URL but different body. Confidential data in the POST's response body would then leak to unauthorized requests. Though the request itself will not be deduped. This is only an issue when receiving request bodies with a content type charset other than UTF-8. For example, the UTF-16 byte sequences for 삃삃 and 섄섄 in the request body would share the same cache. This issue has been fixed in versions 15.5.21 and 16.2.11.

Affected Software

VendorProductVersion RangeStatus
vercelnext.js>= 13.0.0, < 15.5.21affected
vercelnext.js>= 16.0.0, < 16.2.11affected

Weaknesses

  • CWE-116: CWE-116: Improper Encoding or Escaping of Output

ADP Enrichment

CISA ADP Vulnrichment

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

References