CVE-2026-64643
Next.js: Unauthenticated Disclosure of Internal Server Function endpoints
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, Next.js applications using App Router, Server Actions (use server) or use cache endpoints can be disclosed bypassing any authentication on the pages where these endpoints are usually used. Server Action IDs can be disclosed to unauthenticated users via publicly served client artifacts (for example, static chunks containing action references). Affected users are applications using App Router and Server Actions. By itself, this disclosure is typically a recon/enumeration primitive; however, it can increase risk when combined with other weaknesses. This issue has been fixed in versions 15.5.21 and 16.2.11.
INFO
Published Date :
July 27, 2026, 6:16 p.m.
Last Modified :
July 29, 2026, 2:37 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 4.0 | MEDIUM | [email protected] |
Solution
- Update Next.js to version 15.5.21 or 16.2.11.
- Verify App Router and Server Actions are secured.
- Review access controls for client artifacts.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-64643.
| URL | Resource |
|---|---|
| https://github.com/vercel/next.js/commit/1b0c3ae912a3ad925c60065cc8d55b070fa8bcd3 | Patch |
| https://github.com/vercel/next.js/commit/ff12a6124e1504f17b62de948b8a553fdecaef7b | Patch |
| https://github.com/vercel/next.js/releases/tag/v15.5.21 | Product Release Notes |
| https://github.com/vercel/next.js/releases/tag/v16.2.11 | Product Release Notes |
| https://github.com/vercel/next.js/security/advisories/GHSA-955p-x3mx-jcvp | Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-64643 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-2026-64643
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-2026-64643 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-64643 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.
-
Initial Analysis by [email protected]
Jul. 29, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N Added CPE Configuration OR *cpe:2.3:a:vercel:next.js:*:*:*:*:*:node.js:*:* versions from (including) 16.0.0 up to (excluding) 16.2.11 *cpe:2.3:a:vercel:next.js:*:*:*:*:*:node.js:*:* versions from (including) 13.0.0 up to (excluding) 15.5.21 Added Reference Type GitHub, Inc.: https://github.com/vercel/next.js/commit/1b0c3ae912a3ad925c60065cc8d55b070fa8bcd3 Types: Patch Added Reference Type GitHub, Inc.: https://github.com/vercel/next.js/commit/ff12a6124e1504f17b62de948b8a553fdecaef7b Types: Patch Added Reference Type GitHub, Inc.: https://github.com/vercel/next.js/releases/tag/v15.5.21 Types: Product, Release Notes Added Reference Type GitHub, Inc.: https://github.com/vercel/next.js/releases/tag/v16.2.11 Types: Product, Release Notes Added Reference Type GitHub, Inc.: https://github.com/vercel/next.js/security/advisories/GHSA-955p-x3mx-jcvp Types: Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jul. 27, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-64643', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-07-27T18:20:57.639287Z'} -
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, Next.js applications using App Router, Server Actions (use server) or use cache endpoints can be disclosed bypassing any authentication on the pages where these endpoints are usually used. Server Action IDs can be disclosed to unauthenticated users via publicly served client artifacts (for example, static chunks containing action references). Affected users are applications using App Router and Server Actions. By itself, this disclosure is typically a recon/enumeration primitive; however, it can increase risk when combined with other weaknesses. 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:N/VC:L/VI:N/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-201 Added Reference https://github.com/vercel/next.js/commit/1b0c3ae912a3ad925c60065cc8d55b070fa8bcd3 Added Reference https://github.com/vercel/next.js/commit/ff12a6124e1504f17b62de948b8a553fdecaef7b 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-955p-x3mx-jcvp