CVE-2026-64647

A flaw was found in Next.js. This vulnerability allows a remote attacker to potentially access confidential data. When a server-side fetch processes a request with a body using a non-UTF-8 character set, it may incorrectly return a cached response body from a different request to the same URL but different body. This can lead to the unauthorized disclosure of sensitive information.

This Low impact information disclosure flaw affects Next.js applications where server-side fetches handle request bodies with non-UTF-8 charsets. Under these specific conditions, cached responses containing confidential data could be inadvertently exposed to unauthorized requests.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.