SB2026031727 - Multiple vulnerabilities in Next.js



SB2026031727 - Multiple vulnerabilities in Next.js

Published: March 17, 2026

Security Bulletin ID SB2026031727
Severity
Medium
Patch available
YES
Number of vulnerabilities 5
Exploitation vector Remote access
Highest impact Denial of service

Breakdown by Severity

Medium 60% Low 40%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 5 secuirty vulnerabilities.


1) Inconsistent interpretation of HTTP requests (CVE-ID: CVE-2026-29057)

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.


2) Resource management error (CVE-ID: CVE-2026-27979)

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to improper management of internal resources within the application when handling HTTP requests with "next-resume: 1" HTTP header. A remote attacker can send large HTTP POST payloads to the application and to trigger excessive memory usage and cause a denial of service condition. 


3) Missing Origin Validation in WebSockets (CVE-ID: CVE-2026-27977)

The vulnerability allows a remote attacker to perform CSRF attacks.

The vulnerability exists due to incorrect handling of "Origin: null". A remote attacker can bypass dev HMR websocket CSRF checks.


4) Cross-site request forgery (CVE-ID: CVE-2026-27978)

The vulnerability allows a remote attacker to perform cross-site request forgery attacks.

The vulnerability exists due to the "origin: null" is treated as a "missing" origin during Server Action CSRF validation. A remote attacker can trick the victim to visit a specially crafted web page and perform arbitrary actions on behalf of the victim on the vulnerable website.


5) Resource exhaustion (CVE-ID: CVE-2026-27980)

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to the image optimization disk cache (/_next/image) does not have a configurable upper bound, allowing unbounded cache growth. A remote attacker can generate multiple unique image-optimization variants and exhaust disk space leading to a denial of service condition. 


Remediation

Install update from vendor's website.