CVE-2025-54101 is a use-after-free vulnerability classified under CWE-416 affecting the Windows SMBv3 client component in Microsoft Windows 10 Version 1809 (build 17763.0). This vulnerability arises when the SMBv3 client improperly manages memory, leading to a use-after-free condition that can be exploited by an attacker with authorized access to execute arbitrary code remotely over the network. The attack vector requires network access (AV:N), but exploitation complexity is high (AC:H), requiring low privileges (PR:L) and user interaction (UI:R). The vulnerability impacts system availability (A:H) but does not affect confidentiality or integrity. No public exploits are known at this time, and no patches have been released yet. The vulnerability was reserved in July 2025 and published in September 2025. The SMBv3 protocol is widely used for file sharing and network communications in enterprise environments, making this vulnerability relevant for organizations relying on Windows 10 Version 1809. The medium CVSS score of 4.8 reflects the moderate risk due to the exploitation conditions and impact scope.

For European organizations, this vulnerability poses a risk primarily to system availability, potentially causing denial of service or system crashes if exploited. Since SMBv3 is commonly used in enterprise networks for file sharing and inter-device communication, exploitation could disrupt business operations, especially in sectors like finance, manufacturing, and government services that rely on stable network file systems. Although the vulnerability does not compromise confidentiality or integrity, the ability to execute code remotely could be leveraged in multi-stage attacks. Organizations still running Windows 10 Version 1809, which is an older release, are particularly vulnerable. The absence of known exploits reduces immediate risk but does not eliminate the threat, especially as attackers may develop exploits once patches are released or if the vulnerability becomes public knowledge. The requirement for user interaction and low privileges limits the attack surface but does not negate the need for prompt mitigation.

1. Upgrade affected systems from Windows 10 Version 1809 to a supported, patched version of Windows 10 or later to eliminate the vulnerability. 2. Until patches are available, consider disabling the SMBv3 client functionality on vulnerable systems if SMBv3 is not essential, or restrict SMB traffic using network segmentation and firewall rules to limit exposure. 3. Implement strict network access controls to ensure only authorized and trusted users can access SMB services. 4. Educate users about the risks of interacting with unsolicited SMB requests or network shares to reduce the likelihood of user interaction exploitation. 5. Monitor network traffic for unusual SMB activity that could indicate exploitation attempts. 6. Maintain up-to-date endpoint detection and response (EDR) solutions capable of detecting anomalous behaviors related to memory corruption or SMB exploitation. 7. Plan for rapid deployment of official patches once Microsoft releases them, including testing in controlled environments to avoid operational disruptions.