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.

The version of Next.js installed on the remote host is 12.0.0 prior to 15.5.21 or 16.0.0 prior to 16.2.11. It is, therefore, affected by multiple vulnerabilities:

- A Server-Side Request Forgery vulnerability in rewrites via an attacker-controlled destination hostname. (CVE-2026-64645)

- A Server-Side Request Forgery vulnerability in Server Actions on custom servers. This issue only affects versions 14.1.1 and later. (CVE-2026-64649)

- A Middleware / Proxy bypass in App Router applications using Turbopack and a single locale. This issue only affects versions 16.0.0 and later. (CVE-2026-64642)

- A denial of service vulnerability in App Router applications using Server Actions. This issue only affects versions 13.0.0 and later. (CVE-2026-64641)

- A denial of service vulnerability due to unbounded Server Action payloads in the Edge runtime. This issue only affects versions 13.0.0 and later. (CVE-2026-64646)

- A denial of service vulnerability in the Image Optimization API using SVGs. This issue only affects versions 15.5.0 and later. (CVE-2026-64644)

- A cache confusion of response bodies for requests with bodies. This issue only affects versions 13.0.0 and later. (CVE-2026-64648)

- A cache confusion of response bodies for requests with bodies containing invalid UTF-8 byte sequences. This issue only affects versions 13.0.0 and later. (CVE-2026-64647)

- An unauthenticated disclosure of internal Server Function endpoints. This issue only affects versions 13.0.0 and later. (CVE-2026-64643)

Note that the scanner has not attempted to exploit these issues but has instead relied only on application's self-reported version number.

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - 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. (CVE-2026-64647)

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - 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  and  in the request body would share the same cache. This issue has been fixed in     versions 15.5.21 and 16.2.11. (CVE-2026-64647)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Type	Severity
115757	Next.js 16.0.x < 16.2.11 Multiple Vulnerabilities	Web App Scanning	Component Vulnerability	Version Based	high
115756	Next.js 12.0.0 < 15.5.21 Multiple Vulnerabilities	Web App Scanning	Component Vulnerability	Version Based	high
459440	Echo: next: security update to 15.5.21	Tenable Cloud Security	Echo Local Security Checks	Local	medium
459440	Echo: next: security update to 15.5.21	Tenable Self-Hosted Container Security	Echo Local Security Checks	Local	medium
330672	Linux Distros Unpatched Vulnerability : CVE-2026-64647	Nessus	Misc.	Local	medium
445134	SCA: security update for next (GHSA-4633-3j49-mh5q)	Tenable Cloud Security	SCA Checks	Local	medium
445134	SCA: security update for next (GHSA-4633-3j49-mh5q)	Tenable Self-Hosted Container Security	SCA Checks	Local	medium

Detections

Analytics

CVE-2026-64647

medium

Tenable Plugins

high

high

medium

medium

medium

medium

medium