Server-Side Request Forgery (SSRF) in Next.js - CVE-2026-64645
Published: July 22, 2026
Vulnerability identifier: #VU139028
CSH Severity: High
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/SC:L/SI:N/SA:N/E:U/U:Amber
CVE-ID: CVE-2026-64645
CWE-ID: CWE-918
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 perform server-side request forgery.
The vulnerability exists due to improper neutralization of user-controlled input in rewrites() and redirects() destination hostname handling when constructing an external destination hostname from request-controlled input. A remote attacker can send a specially crafted request to perform server-side request forgery.
For rewrite rules, the application proxies the request to the attacker-selected host and serves the response from the application's origin.
How to mitigate CVE-2026-64645
Install security update from vendor's website.