CVE-2025-62455 is a vulnerability categorized under CWE-20 (Improper Input Validation) affecting Microsoft Windows 10 Version 1809, specifically build 17763.0. The flaw resides in the Windows Message Queuing (MSMQ) service, which improperly validates input data. This improper validation can be exploited by an attacker who already has authorized local access to the system to escalate their privileges. The attack vector requires local access but no user interaction, and the attacker needs only low complexity to exploit the vulnerability. Successful exploitation can lead to full compromise of system confidentiality, integrity, and availability, as the attacker can gain elevated privileges and potentially execute arbitrary code or manipulate system processes. The CVSS v3.1 score is 7.8, reflecting a high severity due to the combination of local privilege escalation, high impact on system security properties, and ease of exploitation. No public exploits or active exploitation in the wild have been reported yet, but the vulnerability is published and known since December 2025. The lack of available patches at the time of disclosure increases the urgency for organizations to implement interim mitigations and monitor systems closely. MSMQ is commonly used in enterprise environments for asynchronous messaging, making this vulnerability relevant for organizations relying on legacy Windows 10 deployments.

For European organizations, this vulnerability poses a significant risk especially to those still operating Windows 10 Version 1809 in production environments. Privilege escalation vulnerabilities can enable attackers to bypass security controls, access sensitive data, disrupt services, or deploy ransomware and other malware. Critical sectors such as finance, healthcare, manufacturing, and government agencies that use legacy Windows 10 systems and MSMQ services are particularly vulnerable. The impact extends to confidentiality breaches, integrity violations, and availability disruptions, potentially affecting business continuity and regulatory compliance (e.g., GDPR). The local attack requirement limits remote exploitation but insider threats or attackers with initial footholds could leverage this flaw to deepen their access. The absence of known exploits currently provides a window for proactive defense, but the risk of future exploitation remains high.

Since no official patches are currently available, European organizations should implement the following mitigations: 1) Restrict local access to systems running Windows 10 Version 1809, especially those providing MSMQ services, limiting it to trusted users only. 2) Employ strict access controls and monitoring on MSMQ-related processes and services to detect anomalous activity. 3) Use application whitelisting and endpoint detection and response (EDR) tools to identify and block privilege escalation attempts. 4) Plan and prioritize upgrading affected systems to supported Windows versions with security patches. 5) Conduct regular vulnerability scanning and penetration testing focused on privilege escalation vectors. 6) Implement network segmentation to isolate legacy systems and reduce lateral movement risk. 7) Maintain comprehensive logging and alerting to detect exploitation attempts early. Once Microsoft releases official patches, apply them promptly following thorough testing.