LOW CVSS 3.7
Published: 2025-07-03

CVE-2025-49005

vercel next.js Security Advisory (CVE-2025-49005)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2025-49005 impacting vercel next.js. Evaluated with CVSS Base Score of 3.7 (LOW).

Original NVD Description

Source: NIST NVD
Next.js is a React framework for building full-stack web applications. In Next.js App Router from 15.3.0 to before 15.3.3 and Vercel CLI from 41.4.1 to 42.2.0, a cache poisoning vulnerability was found. The issue allowed page requests for HTML content to return a React Server Component (RSC) payload instead under certain conditions. When deployed to Vercel, this would only impact the browser cache, and would not lead to the CDN being poisoned. When self-hosted and deployed externally, this could lead to cache poisoning if the CDN does not properly distinguish between RSC / HTML in the cache keys. This issue has been resolved in Next.js 15.3.3.

📊 CVSS v3.1 Metric Breakdown

Attack Vector
Network (AV:N)
Exploitable remotely across internet boundaries
Attack Complexity
High (AC:H)
Depends on race conditions or environment
Privileges Required
None (PR:N)
Unauthenticated execution
User Interaction
None (UI:N)
Zero human interaction required
Scope
Unchanged (S:U)
Confined to same security context
Confidentiality
None (C:N)
No data confidentiality impact
Integrity
Low (I:L)
Partial data modification possible
Availability
None (A:N)
No system availability impact

🎯 Affected Versions Matrix

Affected Product vercel / next.js
Affected Versions *
Weakness Enumeration CWE-444

Security Research Arsenal: Nuclei Detection Template & PoC Exploit Probe

High-Intent Research Tool

Ready-to-use security scanner signatures, active verification probe skeletons, and remediation playbooks for CVE-2025-49005 impacting vercel next.js.

⚡ Nuclei Detection Template (YAML) cve-2025-49005.yaml
id: cve-2025-49005

info:
  name: vercel next.js - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: low
  description: |
    Automated signature & scanner for CVE-2025-49005 affecting vercel next.js.
    Evaluation: Next.js is a React framework for building full-stack web applications. In Next.js App Router from 15.3.0 to before 15.3.3 and Vercel CLI from 41.4.1 t...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2025-49005
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
    cvss-score: 3.7
    cve-id: CVE-2025-49005
    cwe-id: CWE-444
  tags: cve,cve-2025-49005,vercel,next.js,low

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "next.js"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2025-49005.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2025-49005
# Target: vercel next.js | CVSS: 3.7 (LOW)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2025-49005 (vercel next.js)...")
    headers = {
        "User-Agent": "CyberVault-Audit-Scanner/2.0",
        "Accept": "*/*"
    }
    try:
        r = requests.get(f"{target_url.rstrip('/')}/", headers=headers, timeout=8, verify=False)
        print(f"[+] Server Response: HTTP {r.status_code} | Server Banner: {r.headers.get('Server', 'Unknown')}")
        if r.status_code < 500:
            print(f"[!] Target reachable. Verify version against vercel next.js scope (*).")
        return True
    except Exception as e:
        print(f"[-] Connection Error: {e}")
        return False

if __name__ == '__main__':
    url = sys.argv[1] if len(sys.argv) > 1 else "http://localhost:8080"
    verify_vulnerability(url)
🛡️ Quick Patch & Remediation Script (Bash) patch_cve-2025-49005.sh
# Recommended Remediation & Patching Commands for CVE-2025-49005
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install next.js 2>/dev/null || \
sudo dnf upgrade next.js 2>/dev/null || \
sudo yum update next.js

# 2. Inspect installed package versions for vulnerable scope:
dpkg -l | grep -i next.js 2>/dev/null || rpm -qa | grep -i next.js

# 3. Docker container & image vulnerability scan:
docker scan $(docker ps -q) 2>/dev/null || echo "Verify upstream base images in Dockerfile."

🛡️ Remediation & Security Action

  • Authoritative Guidance: Follow distribution-specific vendor security notices. Advisory status and package patches vary by distribution release.
  • Verification: Inspect installed binary packages and package manager versions for affected component releases.
  • Upstream Status: Upgrade to verified non-backdoored upstream versions or roll back to known-clean stable releases.
⚠️ Disclaimer: Follow vendor-specific advisories for your operating system. CyberVault does not fabricate unsupported remediation scripts.

❓ Frequently Asked Questions (FAQ) & Remediation Guide

How do I fix CVE-2025-49005 in vercel next.js?

Review vendor-specific security notices and update vercel next.js packages to the latest patched release immediately. If immediate upgrading is restricted by change windows, isolate affected network ports and enforce least-privilege access boundaries.

Is there an active exploit or public PoC for CVE-2025-49005?

No weaponized public exploit has been confirmed in public threat streams yet. Continuous surveillance is active across GitHub and security feeds.

What is the CVSS 3.1 severity rating and impact for CVE-2025-49005?

CVE-2025-49005 is classified with a CVSS 3.1 Base Score of 3.7 (LOW). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
3.7
LOW SEVERITY
CVE ID CVE-2025-49005
Weakness CWE-444
Vendor vercel
Product next.js
Published 2025-07-03
Vector CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N