Next Js
CVE-2021-39178
MEDIUM
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A05:2025 - Injection
ASVS 5.0
V1 - Encoding and Sanitization Output encoding, context-aware escaping
MITRE ATT&CK
2 techniques across 2 tactics: Initial Access, Execution The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Impact | CVSS score of 6.1 (MEDIUM). Attack characteristics: network attack vector, low complexity, no privileges required, user interaction required. |
| Exploit ScenarioDerived | A remote attacker could inject malicious scripts into web pages viewed by other users by sending crafted requests to the affected application. No authentication is required to exploit this vulnerability. |
Get an e-mail when this CVE is exploited, patched or re-scored. Free account.
Alert meAnalysisAI
Next.js is a React framework. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This Cross-Site Scripting (XSS) vulnerability could allow attackers to inject malicious scripts into web pages viewed by other users.
RemediationAI
A vendor patch is available. Apply the latest security update as soon as possible. Sanitize all user input, use Content-Security-Policy headers, encode output contextually (HTML, JS, URL). Use frameworks with built-in XSS protection.
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 1 package in npm
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
This vulnerability is classified as Cross-Site Scripting (XSS) (CWE-79), which allows attackers to inject malicious scripts into web pages viewed by other users. Next.js is a React framework. Versions of Next.js between 10.0.0 and 11.0.0 contain a cross-site scripting vulnerability. In order for an instance to be affected by the vulnerability, the next.config.js file must have images.domains array assigned and the image host assigned in images.domains must allow user-provided SVG. If the next.config.js file has images.loader assigned to something other than default or the instance is deployed on Vercel, the instance is not affected by the vulnerability. The vulnerability is patched in Next.js version 11.1.1. Affected products include: Vercel Next.Js. Version information: version 11.1.1..
Know when Next Js gets its next vulnerability
- Watch products and get an email when something new is published
- Check this CVE against your own stack and servers
- Exploit and PoC references, threat intelligence from 22 sources
No credit card · 7-day full trial
Severity by source
AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
DescriptionNVD
Next.js is a React framework. Versions of Next.js between 10.0.0 and 11.0.0 contain a cross-site scripting vulnerability. In order for an instance to be affected by the vulnerability, the next.config.js file must have images.domains array assigned and the image host assigned in images.domains must allow user-provided SVG. If the next.config.js file has images.loader assigned to something other than default or the instance is deployed on Vercel, the instance is not affected by the vulnerability. The vulnerability is patched in Next.js version 11.1.1.
Threat Intelligence Overview
NVD
CVE.org
EPSS
GitHub
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Cross-Site Scripting occurs when an application accepts untrusted data and sends it to a web browser without proper validation or encoding.
Affected Products (CPE)NVD
React Server Components in React 19.x contain a critical pre-authentication remote code execution vulnerability (CVE-202
ZEIT Next.js before 2.4.1 has directory traversal under the /_next and /static request namespace, allowing attackers to
Pre-authentication denial of service in React Server Components (versions 19.0.0 through 19.2.1) allows unauthenticated
Information disclosure in React Server Components 19.x, distributed as react-server-dom-webpack, react-server-dom-turbop
Path traversal in Next.js (13.4.0 through 15.5.23 and 16.x before 16.3.3) running on Windows-hosted servers lets a remot
Server-side request forgery in Vercel Next.js affects self-hosted deployments whose custom middleware calls next()/NextR
Next.js is a React framework that can provide building blocks to create web applications. Rated high severity (CVSS 7.5)
Next.js before 13.4.20-canary.13 lacks a cache-control header and thus empty prefetch responses may sometimes be cached
ZEIT Next.js 4 before 4.2.3 has Directory Traversal under the /_next request namespace. Rated high severity (CVSS 7.5),
Unsafe deserialization in React Server Components Server Function endpoints allows remote unauthenticated attackers to t
Server-side request forgery in the Next.js Image Optimization endpoint lets a remote, unauthenticated attacker cause the
Next.js versions before 9.3.2 have a directory traversal vulnerability. Rated medium severity (CVSS 4.3), this vulnerabi
Exploit-DB