CVE-2026-48770 MEDIUM

CVE-2026-48770: Notepad++ WM_COPYDATA COPYDATA_FULL_CMDLINE local DoS crash

Vendor Notepad-Plus-Plus
Product notepad-plus-plus
Weakness CWE-125
Published June 26, 2026
Last update June 29, 2026
View on NVD All CVEs

CVSS base score

5.0/10
Attack vector Local
Attack complexity Low
Privileges required Low
User interaction Required
Confidentiality None
Integrity None

CVSS vector

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

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

June 26, 2026 CVE published
June 29, 2026 Record updated