Improper Validation of Array Index in Notepad++ - #VU151929
Published: September 24, 2026
Vulnerability identifier: #VU151929
CSH Severity: Low
CVSS v4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-129
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to improper validation of an array index in the NPPM_SETCURRENTLANGTYPE handler when processing a negative LangType value. A local user can send a specially crafted NPPM message to cause a denial of service.
Direct NPPM message delivery is limited to same-integrity processes.
Affected software
Notepad++
Remediation
Install security update from vendor's website.
Notepad++ - update to 8.9.8.1