Inconsistent interpretation of HTTP requests in Next.js - CVE-2026-29057
Published: March 17, 2026
Vulnerability identifier: #VU124061
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-29057
CWE-ID: CWE-444
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to perform HTTP request smuggling attacks.
The vulnerability exists due to improper validation of HTTP requests. A remote attacker can send a specially crafted DELETE/OPTIONS HTTP request using Transfer-Encoding: chunked to the server and smuggle arbitrary HTTP headers.
Successful exploitation of vulnerability may allow an attacker to poison HTTP cache and perform phishing attacks.
Affected software
Next.js
How to mitigate CVE-2026-29057
Install updates from vendor's website.
Next.js - addressed in versions 15.5.13, 16.1.7