Stack-based buffer overflow in Notepad++ - CVE-2026-54758
Published: July 14, 2026
Vulnerability identifier: #VU137489
CSH Severity: High
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber
CVE-ID: CVE-2026-54758
CWE-ID: CWE-121
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Notepad++
Affected software:
Notepad++
Notepad++
Detailed vulnerability description
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to stack-based buffer overflow in expandNppEnvironmentStrs when parsing a variable name in the Run dialog input. A remote attacker can trick the victim into processing a specially crafted variable reference to cause a denial of service.
User interaction is required to open the Run dialog and submit crafted input.
How to mitigate CVE-2026-54758
Install security update from vendor's website.