CVE-2026-52885
MediumCVSS 6.3Exploitation Probability (EPSS)
Low risk6th percentile — higher than 6% of all known CVEs
Summary
In Notepad++ prior to 8.9.6.4, a TOCTOU vulnerability exists in handling shortcuts.xml. The HMAC check occurs at command execution time, but the command payload is taken from memory that is not synchronized with the disk file. An attacker can swap the file before launch and restore it afterward, allowing malicious commands to execute.
Risk Assessment
The organization is at risk of unauthorized command execution by an attacker with local access to the configuration file. This could lead to privilege escalation, malicious code execution, or system integrity compromise.
Recommendation
Update Notepad++ to version 8.9.6.4 or later immediately. Additionally, restrict write permissions to shortcuts.xml to trusted users only.
Original NVD description (English source)
Notepad++ is a free and open-source source code editor. Prior to 8.9.6.4, NppCommands.cpp checks the HMAC of the on-disk shortcuts.xml at the moment a user command fires (Time-of-Check). However, the command payload is taken from the in-memory _userCommands vector, which is populated at application startup and never re-synchronized with the on-disk file (Time-of-Use). Swapping shortcuts.xml between startup and command execution causes the HMAC check to validate a clean file while a malicious command runs. An attacker with write access to shortcuts.xml places a malicious version on disk before launch, then immediately restores the legitimate file. The HMAC check at execution time validates the restored legitimate file (check passes), while the malicious payload executes from memory. This vulnerability is fixed in 8.9.6.4.