CVE-2026-2538 is a vulnerability identified in Flos Freeware Notepad2 versions 4.2.22 to 4.2.25, specifically related to an uncontrolled search path issue within the Msimg32.dll library. This vulnerability arises when the application loads DLLs or other resources without properly validating or controlling the search path, allowing an attacker with local access to influence which DLL is loaded. The attack complexity is high, indicating that exploitation requires detailed knowledge and specific conditions, and the exploitability is difficult. The attacker must have at least limited privileges on the local machine but does not require user interaction or elevated authentication. Successful exploitation could lead to execution of arbitrary code with the privileges of the Notepad2 process, potentially enabling privilege escalation or persistence on the system. The vendor was notified early but has not issued any response or patch, and no known exploits are currently in the wild. The vulnerability has a CVSS 4.0 score of 7.3, reflecting its high severity primarily due to the potential impact on confidentiality, integrity, and availability, combined with the local attack vector and high complexity. The lack of patch availability increases the risk for organizations relying on these versions of Notepad2. Given that Notepad2 is a lightweight text editor often used in development and administrative contexts, the vulnerability could be leveraged in multi-user environments or by malicious insiders.

For European organizations, the impact of CVE-2026-2538 could be significant in environments where Notepad2 is used, especially in IT, development, or administrative roles where local access is common. An attacker with local access could exploit this vulnerability to execute arbitrary code, potentially leading to privilege escalation or unauthorized persistence. This could compromise sensitive data, disrupt operations, or serve as a foothold for further attacks within the network. Organizations with shared workstations, remote desktop environments, or insufficient local access controls are particularly at risk. The absence of a vendor patch means that the vulnerability remains exploitable, increasing the window of exposure. While the attack complexity is high and exploitation is difficult, insider threats or attackers who have already gained limited access could leverage this flaw to escalate privileges or move laterally. This could impact confidentiality, integrity, and availability of systems and data, especially in sectors with stringent data protection requirements such as finance, healthcare, and government.

1. Restrict local access to systems running affected versions of Notepad2, ensuring only trusted users have login permissions. 2. Employ application whitelisting and restrict execution of unauthorized DLLs or binaries in user directories to prevent malicious DLL injection. 3. Monitor system logs and use endpoint detection and response (EDR) tools to detect unusual DLL loading or process behavior related to Notepad2. 4. Consider temporarily replacing Notepad2 with alternative, actively maintained text editors that do not exhibit this vulnerability. 5. Implement strict file system permissions to prevent unauthorized users from placing malicious DLLs in directories searched by Notepad2. 6. Educate users about the risks of running untrusted code locally and enforce least privilege principles. 7. Regularly audit installed software versions and maintain an inventory to quickly identify vulnerable instances. 8. Stay alert for vendor updates or community patches and apply them promptly once available.