The flaw is located in Notepad3’s About dialog; the program calls LoadLibrary with the bare name "MSFTEDIT.DLL". Because an attacker with local access can place a malicious copy of MSFTEDIT.DLL in the application folder or another DLL search path, the loader will load the legitimate system library and execute arbitrary code in the context of the user opening the dialog. This is a classic DLL search‑order hijacking vulnerability (CWE‑427) that can compromise the entire user session if exploited.

All releases of Notepad3 through version 6.25.822.1 are affected. Users running these versions should verify their installed version and apply any available update from the official source.

The flaw requires local file placement and the user to open the About dialog, so there is no remote exploitation vector. The EPSS score of less than 1 % and absence from the CISA KEV catalog indicate a low likelihood of exploitation. The CVSS score of 7.8 reflects the potential impact within the affected user’s session.