Excessive Iteration in Next.js - CVE-2026-64641
Published: July 22, 2026
Vulnerability identifier: #VU139033
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-64641
CWE-ID: CWE-834
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: vercel
Affected software:
Next.js
Next.js
Detailed vulnerability description
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to excessive iteration in App Router server actions handling when processing crafted requests. A remote attacker can send crafted requests to cause a denial of service.
Only applications using App Router with at least one Server Action are vulnerable.
How to mitigate CVE-2026-64641
Install security update from vendor's website.