CVE-2026-77605 Notepad++ “Run by system” executes *.txt.cmd when user selected *.txt (target confusion → command execution)
Attackers can execute arbitrary commands by tricking Notepad++ into running a malicious sibling script when a user selects a text file.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-77605?
CVE-2026-77605 is a high-severity command injection vulnerability in notepad-plus-plus, published on 22 Sep 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
Notepad++ is a free and open-source source code editor. Prior to 8.9.8, the Folder as Workspace Run by system action in Notepad++ can resolve a different sibling file than the file selected by the user. When an attacker places a command script whose name is the selected text-file path with .cmd appended, and the user invokes Run by system on the text file on Windows 10 or Windows 11, Notepad++ can execute the sibling script as the current user instead of opening the selected file. This issue is fixed in version 8.9.8.
Which versions are affected by CVE-2026-77605?
How do I fix CVE-2026-77605?
No fix has been published for CVE-2026-77605 yet. Limit exposure of the affected software until one is available.
Upgrade, and pass arguments to programs as a list instead of through a shell. More about Command injection.
Is CVE-2026-77605 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-77605 exists.
Sources
Also known as GHSA-w5xq-frjg-w4cw.