CVE-2026-48770

Description

A local process in the same interactive Windows session can send a malformed WM_COPYDATA message to Notepad++ using the COPYDATA_FULL_CMDLINE path, causing a denial of service crash.

Description (MITRE) cveawg.mitre.org

Pulled from cveawg.mitre.org/api/cve/CVE-2026-48770 on 2026-06-30. Shown when MITRE's text differs from the cvelistV5 mirror.

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.

Overview

State

—

Assigner (CNA)

—

CVSS severity

MEDIUM

CVSS score

5.0 / 10

CVSS vector

AV:L/AC:L/Au:N/C:N/I:N/A:C

Effective score

5.0 / 10 MEDIUM source: CNA overview

CWE(s)

—

Reserved

—

Published

2026-05-26 00:00 UTC

Last updated

—

Source

https://www.rapid7.com/db/vulnerabilities/notepad-plus-plus-cve-2026-48770/

Linked Threat

CVE-2026-48770 — CVE-2026-48770

NVD triage scoring NVD CVE 2.0

Layer NVD adds on top of the CNA's CVE record — published / last-modified timestamps, exploitability / impact subscores, and the FIRST.org EPSS probability that this CVE will be exploited in the wild in the next 30 days.

NVD published

2026-06-26 21:16:34 UTC

NVD last modified

2026-06-29 21:21:52 UTC

NVD CVSS v3.1

5.0 / 10 MEDIUM source: security-advisories@github.com

NVD CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H

Exploitability subscore

1.3 / 10

Impact subscore

3.6 / 10

EPSS score

0.0026 (probability of exploitation in next 30 days)

EPSS percentile

17.09% vs all CVEs — higher = more likely to be exploited, as of 2026-06-30

NVD-assigned CWE(s): CWE-125 (differs from the CNA list above)

European Union Vulnerability Database ENISA EUVD

ENISA's official EU repository for curated vulnerability intelligence. Carries a separate identifier (EUVD-YYYY-NNNN) and frequently exposes an earlier-published description + CVSS than NVD does.

EUVD ID

EUVD-2026-39908

Assigner

GitHub_M

Published

Jun 26, 2026, 8:22:17 PM

Updated

Jun 29, 2026, 12:11:59 PM

EUVD base score (CVSS 3.1)

5.0 / 10
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H

EUVD-reported EPSS

0.2600

Vendors

notepad-plus-plus

Products

notepad-plus-plus (< 8.9.6.1)

ENISA description: 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.

Vendor references (0)

References embedded in the original CVE record by the assigning CNA.

None in the CVE record.

MITRE references (1) cveawg.mitre.org

Pulled from MITRE's CVE Services API by the 🛰 Backfill from MITRE button.

• https://github.com/notepad-plus-plus/notepad-plus-plus/commit/f20a0888a92ce557a339b833cd9d9d8e97dc797d x_refsource_MISC

Web references (5)

DuckDuckGo results ranked by threat-intel / vendor advisory domains. Generated by the 🔎 Find references (web) button above — same flow as the Remediations search.

• https://nvd.nist.gov/vuln/detail/CVE-2026-48770 tenable:nvd.nist.gov
• https://attackerkb.com/topics/CVE-2026-48770 rapid7:attackerkb.com
• https://github.com/notepad-plus-plus/notepad-plus-plus/security/advisories/GHSA-r39g-3mcw-xcg2 rapid7:github.com
• https://notepad-plus-plus.org/news/v8961-released/ rapid7:notepad-plus-plus.org
• https://www.cve.org/CVERecord?id=CVE-2026-48770 rapid7:www.cve.org

Remediations are stored against the linked Threat row; the list below is deduplicated across both pages.

• Rapid7 — Solution
  rapid7

  notepadplusplus-upgrade

  2026-06-04 09:01 UTC
• Security Update Guide - Microsoft Security Response Center
  web:msrc.microsoft.com

  Security Update Guide - Microsoft Security Response Center

  2026-06-19 02:34 UTC
• Nvd - Cve-2026-48777
  web:nvd.nist.gov

  An official website of the United States government Here's how you know

  2026-06-19 02:34 UTC
• Security Update Guide - Loading - Microsoft
  web:portal.msrc.microsoft.com

  The Security Update Guide provides information on the latest Microsoft security updates, helping users understand and address potential vulnerabilities effectively.

  2026-06-19 02:34 UTC
• Notepad++ Fixes CVE-2026-48770 RCE Vulnerability
  web:thecyberexpress.com

  Notepad++ patches CVE - 2026 -48778, CVE-2026-48770 , and CVE - 2026 -48800 flaws that could enable RCE and command injection attacks.

  2026-06-19 02:34 UTC
• CISA Adds One Known Exploited Vulnerability to Catalog
  web:www.cisa.gov

  BOD 26-04 further establishes basic expectations for when agencies must check whether threat actors compromised the system before the patch was applied. While BOD 26-04 applies only to FCEB agencies, CISA encourages all organizations to adopt risk-based vulnerability management and prioritize remediation of KEV catalog vulnerabilities.

  2026-06-19 02:34 UTC
• Oracle Critical Patch Update Advisory - April 2026
  web:www.oracle.com

  This Critical Patch Update contains 481 new security patches across the product families listed below. Please note that an MOS note summarizing the content of this Critical Patch Update and other Oracle Software Security Assurance activities is located at April 2026 Critical Patch Update: Executive Summary and Analysis.

  2026-06-19 02:34 UTC
• Oracle Critical Security Patch Update Advisory - May 2026
  web:www.oracle.com

  This Critical Security Patch Update contains 35 new security patches across the product families listed below. Please note that an MOS note summarizing the content of this Critical Security Patch Update and other Oracle Software Security Assurance activities is located at May 2026 Critical Security Patch Update: Executive Summary and Analysis.

  2026-06-19 02:34 UTC
• Patch Tuesday - June 2026 - Rapid7
  web:www.rapid7.com

  Microsoft is publishing 200 vulnerabilities on June 2026 Patch Tuesday, including an HTTP/2 denial of service vulnerability and an elevation of privilege vulnerability in PowerToys.

  2026-06-19 02:34 UTC
• Vulnerabilities Resolved in Veeam Backup & Replication 13.0.1.2067
  web:www.veeam.com

  When a vulnerability is identified, our team promptly develops a patch to address and mitigate the risk. In line with our dedication to transparency, we publicly disclose the vulnerability and provide detailed mitigation information.

  2026-06-19 02:34 UTC
• Patch Tuesday June 2026: Security Updates & CVE Analysis
  web:zecurit.com

  Get the complete breakdown of Microsoft's June 2026 Patch Tuesday. We analyze the latest security updates and all critical CVEs .

  2026-06-19 02:34 UTC

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