6.0
MEDIUM CVSS 4.0
CVE-2026-64648
Next.js: Response Body Cache Confusion for Requests Containing Bodies
Description

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 only applies to fetch calls with a request that has a different init than the one passed to fetch. A safe request would be: fetch(new Request(init), init). An unsafe request would be: fetch(new Request(init), aDifferentInit). This issue has been fixed in versions 15.5.21 and 16.2.11.

INFO

Published Date :

July 27, 2026, 8:16 p.m.

Last Modified :

July 27, 2026, 8:16 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-64648 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Vercel next.js
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 4.0 MEDIUM [email protected]
Solution
Update Next.js to a patched version to prevent cached response leakage.
  • Update Next.js to version 15.5.21 or later.
  • Update Next.js to version 16.2.11 or later.
  • Ensure fetch calls use consistent request initialization.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-64648 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-64648 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-64648 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-64648 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Jul. 27, 2026

    Action Type Old Value New Value
    Added Affected [{'vendor': 'vercel', 'product': 'next.js', 'versions': [{'status': 'affected', 'version': '>= 13.0.0, < 15.5.21'}, {'status': 'affected', 'version': '>= 16.0.0, < 16.2.11'}]}]
    Added Description 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 only applies to fetch calls with a request that has a different init than the one passed to fetch. A safe request would be: fetch(new Request(init), init). An unsafe request would be: fetch(new Request(init), aDifferentInit). This issue has been fixed in versions 15.5.21 and 16.2.11.
    Added CVSS V4.0 AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CWE CWE-524
    Added Reference https://github.com/vercel/next.js/commit/062f66700b52a5d6bba2c0605d55577ab7ad262c
    Added Reference https://github.com/vercel/next.js/commit/73b94872bc343d09494b50394d8c08eb9fc8e56a
    Added Reference https://github.com/vercel/next.js/releases/tag/v15.5.21
    Added Reference https://github.com/vercel/next.js/releases/tag/v16.2.11
    Added Reference https://github.com/vercel/next.js/security/advisories/GHSA-68g3-v927-f742
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.