Time-of-check Time-of-use (TOCTOU) Race Condition in Notepad++ - #VU133403
Published: June 5, 2026
Vulnerability identifier: #VU133403
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/U:Green
CVE-ID: N/A
CWE-ID: CWE-367
Exploitation vector: Remote access
Exploit availability:
Public exploit is available
Vendor: Notepad++
Affected software:
Notepad++
Notepad++
Detailed vulnerability description
The vulnerability allows a remote attacker to compromise the target system.
The vulnerability exists due to a time-of-check, time-of-use (TOCTOU) race condition between HMAC validation and command execution. A remote user can execute arbitrary commands on the target system.
Remediation
Install updates from vendor's website.