SB2026031727 - Multiple vulnerabilities in Next.js

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Main Vulnerability Database SB2026031727

SB2026031727 - Multiple vulnerabilities in Next.js

Published: March 17, 2026

Security Bulletin ID SB2026031727
CSH 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 vulnerabilities.


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

CWE-ID: CWE-444 - Inconsistent Interpretation of HTTP Requests ('HTTP Request Smuggling')

CVSSv4: 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/E:U/U:Green


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)

CWE-ID: CWE-399 - Resource Management Errors

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:L/E:U/U:Green


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)

CWE-ID: CWE-1385 - Missing Origin Validation in WebSockets

CVSSv4: CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N/E:U/U:Clear


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)

CWE-ID: CWE-352 - Cross-Site Request Forgery (CSRF)

CVSSv4: CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N/E:U/U:Clear


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)

CWE-ID: CWE-400 - Resource exhaustion

CVSSv4: 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


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.

References