MEDIUM CVSS 5.0
Published: 2026-06-26

CVE-2026-48770

notepad-plus-plus notepad\+\+ Security Advisory (CVE-2026-48770)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2026-48770 impacting notepad-plus-plus notepad\+\+. Evaluated with CVSS Base Score of 5.0 (MEDIUM).

Original NVD Description

Source: NIST NVD
Notepad++ is a free and open-source source code editor. Prior to 8.9.6.1, a local process in the same interactive Windows session can send a malformed WM_COPYDATA message to Notepad++ using the COPYDATA_FULL_CMDLINE path. The handler appears to process COPYDATASTRUCT.lpData as an unbounded NUL-terminated wchar_t* instead of enforcing COPYDATASTRUCT.cbData. This vulnerability is fixed in 8.9.6.1.

📊 CVSS v3.1 Metric Breakdown

Attack Vector
Local (AV:L)
Requires local system execution permissions
Attack Complexity
Low (AC:L)
No specialized conditions required
Privileges Required
Low (PR:L)
Standard user access required
User Interaction
Required (UI:R)
User must click or open resource
Scope
Unchanged (S:U)
Confined to same security context
Confidentiality
None (C:N)
No data confidentiality impact
Integrity
None (I:N)
No system modification impact
Availability
High (A:H)
Total denial of service or shutdown

🎯 Affected Versions Matrix

Affected Product notepad-plus-plus / notepad\+\+
Affected Versions *
Weakness Enumeration CWE-125

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-2026-48770 impacting notepad-plus-plus notepad\+\+.

⚡ Nuclei Detection Template (YAML) cve-2026-48770.yaml
id: cve-2026-48770

info:
  name: notepad-plus-plus notepad\+\+ - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: medium
  description: |
    Automated signature & scanner for CVE-2026-48770 affecting notepad-plus-plus notepad\+\+.
    Evaluation: Notepad++ is a free and open-source source code editor. Prior to 8.9.6.1, a local process in the same interactive Windows session can send a malformed...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2026-48770
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H
    cvss-score: 5.0
    cve-id: CVE-2026-48770
    cwe-id: CWE-125
  tags: cve,cve-2026-48770,notepad-plus-plus,notepad\+\+,medium

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "notepad\+\+"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2026-48770.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2026-48770
# Target: notepad-plus-plus notepad\+\+ | CVSS: 5.0 (MEDIUM)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2026-48770 (notepad-plus-plus notepad\+\+)...")
    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 notepad-plus-plus notepad\+\+ 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-2026-48770.sh
# Recommended Remediation & Patching Commands for CVE-2026-48770
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install notepad\+\+ 2>/dev/null || \
sudo dnf upgrade notepad\+\+ 2>/dev/null || \
sudo yum update notepad\+\+

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

# 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-2026-48770 in notepad-plus-plus notepad\+\+?

Review vendor-specific security notices and update notepad-plus-plus notepad\+\+ 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-2026-48770?

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-2026-48770?

CVE-2026-48770 is classified with a CVSS 3.1 Base Score of 5.0 (MEDIUM). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
5.0
MEDIUM SEVERITY
CVE ID CVE-2026-48770
Weakness CWE-125
Vendor notepad-plus-plus
Product notepad\+\+
Published 2026-06-26
Vector CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H