Excessive Iteration in Next.js - CVE-2026-64641

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Main Vulnerability Database Vulnerabilities #VU139033

Excessive Iteration in Next.js - CVE-2026-64641

Published: July 22, 2026


Vulnerability identifier: #VU139033
CSH Severity: Medium
CVSS v4: 8.7 [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]
CVE-ID: CVE-2026-64641
CWE-ID: CWE-834
Exploitation vector: Remote access
Exploit availability: No public exploit available

Vulnerability details

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.


Affected software

Next.js
Event Processing

How to mitigate CVE-2026-64641

Install security update from vendor's website.

Next.js - addressed in versions 15.5.21, 16.2.11
Event Processing - update to 1.5.5

External References

Related Security Bulletins