HIGH CVSS 7.5
Published: 2026-06-22

CVE-2025-66389

microsoft github_copilot Security Advisory (CVE-2025-66389)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2025-66389 impacting microsoft github_copilot. Evaluated with CVSS Base Score of 7.5 (HIGH).

Original NVD Description

Source: NIST NVD
GitHub Copilot 1.372.0 allows filesystem access outside of a workspace folder (without user approval) via a file-handler URI parameter to fetch_webpage. Therefore, exfiltration could occur if there is indirect prompt injection.

📊 CVSS v3.1 Metric Breakdown

Attack Vector
Network (AV:N)
Exploitable remotely across internet boundaries
Attack Complexity
Low (AC:L)
No specialized conditions required
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
High (C:H)
Total information disclosure
Integrity
None (I:N)
No system modification impact
Availability
None (A:N)
No system availability impact

🎯 Affected Versions Matrix

Affected Product microsoft / github_copilot
Affected Versions 1.372.0
Weakness Enumeration CWE-552

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-2025-66389 impacting microsoft github_copilot.

⚡ Nuclei Detection Template (YAML) cve-2025-66389.yaml
id: cve-2025-66389

info:
  name: microsoft github_copilot - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: high
  description: |
    Automated signature & scanner for CVE-2025-66389 affecting microsoft github_copilot.
    Evaluation: GitHub Copilot 1.372.0 allows filesystem access outside of a workspace folder (without user approval) via a file-handler URI parameter to fetch_webpag...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2025-66389
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
    cvss-score: 7.5
    cve-id: CVE-2025-66389
    cwe-id: CWE-552
  tags: cve,cve-2025-66389,microsoft,github_copilot,high

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "github_copilot"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2025-66389.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2025-66389
# Target: microsoft github_copilot | CVSS: 7.5 (HIGH)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2025-66389 (microsoft github_copilot)...")
    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 microsoft github_copilot scope (1.372.0).")
        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-2025-66389.sh
# Recommended Remediation & Patching Commands for CVE-2025-66389
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install github_copilot 2>/dev/null || \
sudo dnf upgrade github_copilot 2>/dev/null || \
sudo yum update github_copilot

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

# 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-2025-66389 in microsoft github_copilot?

Review vendor-specific security notices and update microsoft github_copilot 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-2025-66389?

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-2025-66389?

CVE-2025-66389 is classified with a CVSS 3.1 Base Score of 7.5 (HIGH). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
7.5
HIGH SEVERITY
CVE ID CVE-2025-66389
Weakness CWE-552
Vendor microsoft
Product github_copilot
Published 2026-06-22
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N