CVE-2026-4545 identifies a security vulnerability in Flos Freeware Notepad2 version 4.2.25, specifically related to an uncontrolled search path in the PROPSYS.dll library. This vulnerability arises when the application or its components load DLLs or other resources without properly validating or restricting the search path, potentially allowing an attacker with local access to influence which DLL is loaded. This can lead to execution of malicious code with the privileges of the user running Notepad2. The attack complexity is high, indicating that exploitation requires significant skill or specific conditions. The vulnerability does not require user interaction or authentication beyond local access, but the scope is limited to local users. The CVSS 4.0 base score of 7.3 reflects high severity, with high impact on confidentiality, integrity, and availability. The vendor was notified but has not issued a patch or response, and no known exploits have been reported in the wild. The lack of patch availability means that affected users remain exposed if local attackers exist. The flaw is rooted in improper handling of DLL search paths, a common vector for DLL hijacking attacks, which can be leveraged to escalate privileges or execute arbitrary code.

The vulnerability could allow a local attacker to execute arbitrary code by manipulating the DLL search path, potentially leading to privilege escalation or unauthorized actions within the context of the affected user. This compromises confidentiality, integrity, and availability of the system. Although exploitation is difficult and requires local access, environments where multiple users share systems or where local access is not tightly controlled are at risk. The absence of vendor response and patches increases exposure duration. Organizations relying on Notepad2 4.2.25 may face risks of local compromise, lateral movement, or persistence by attackers. The impact is particularly relevant in enterprise or shared workstation environments where local user privileges are sensitive. While no remote exploitation is possible, insider threats or malware with local foothold could leverage this vulnerability.

Since no official patch is available, organizations should implement strict local access controls to limit who can log into systems running Notepad2 4.2.25. Employ application whitelisting and restrict execution permissions in directories where Notepad2 and its DLLs reside. Use tools to monitor and detect anomalous DLL loading behavior or unauthorized file modifications in the application directory. Consider replacing Notepad2 4.2.25 with alternative text editors that do not exhibit this vulnerability. If possible, run Notepad2 with least privilege and avoid running it with elevated rights. Employ endpoint detection and response (EDR) solutions to detect suspicious local activity indicative of DLL hijacking attempts. Regularly audit local user accounts and remove unnecessary privileges. Finally, maintain awareness for any future vendor updates or third-party patches addressing this issue.