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.
Advisories
No advisories yet.
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Mon, 29 Jun 2026 20:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Notepad-plus-plus
Notepad-plus-plus notepad++ |
|
| Vendors & Products |
Notepad-plus-plus
Notepad-plus-plus notepad++ |
Mon, 29 Jun 2026 14:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
|
Fri, 26 Jun 2026 21:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | 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. | |
| Title | Notepad++ TOCTOU: HMAC Checks Disk, Executes from Memory | |
| Weaknesses | CWE-367 | |
| References |
| |
| Metrics |
cvssV4_0
|
Projects
Sign in to view the affected projects.
Status: PUBLISHED
Assigner: GitHub_M
Published:
Updated: 2026-06-29T13:13:00.645Z
Reserved: 2026-06-08T21:44:27.365Z
Link: CVE-2026-52885
Updated: 2026-06-29T13:12:56.130Z
No data.
No data.
OpenCVE Enrichment
Updated: 2026-06-29T19:45:02Z
Weaknesses