CVE-2025-55686 is a use-after-free vulnerability classified under CWE-416 found in the Windows PrintWorkflowUserSvc service of Microsoft Windows 11 Version 25H2 (build 10.0.26200.0). This vulnerability arises when the service improperly manages memory, freeing an object while it is still in use, which can lead to execution of arbitrary code or corruption of memory. An attacker with authorized local access and low privileges can exploit this flaw to elevate their privileges to higher levels, potentially SYSTEM level, thereby gaining control over the affected system. The vulnerability does not require user interaction but does require the attacker to have some level of local access and privileges, making remote exploitation unlikely without prior foothold. The CVSS v3.1 base score is 7.0, reflecting high severity due to the impact on confidentiality, integrity, and availability, although the attack complexity is high and privileges are required. No public exploits or patches are currently available, increasing the urgency for organizations to monitor and prepare mitigations. The flaw specifically targets the PrintWorkflowUserSvc, a service involved in print workflow management, which is commonly enabled in Windows 11 environments, especially in enterprise settings.

For European organizations, this vulnerability poses a significant risk as it enables local privilege escalation, potentially allowing attackers to gain administrative control over affected systems. This can lead to unauthorized access to sensitive data, disruption of services, and deployment of further malware or ransomware. Organizations relying on Windows 11 25H2 for critical operations, especially those with complex printing workflows or multi-user environments, may face increased exposure. The ability to elevate privileges locally can facilitate lateral movement within networks, undermining endpoint security and increasing the risk of widespread compromise. Given the high adoption rate of Windows 11 in Europe, particularly in corporate and governmental sectors, the impact could be substantial if exploited. The absence of known exploits in the wild currently provides a window for proactive defense, but the lack of patches means organizations must rely on compensating controls until updates are released.

1. Restrict local access to systems running Windows 11 Version 25H2, especially limiting access to trusted users only. 2. Implement strict privilege management policies to minimize the number of users with local low-level privileges that could exploit this vulnerability. 3. Monitor event logs and system behavior for anomalies related to the PrintWorkflowUserSvc service, including unexpected crashes or memory errors. 4. Employ application whitelisting and endpoint detection and response (EDR) solutions to detect and block suspicious activities indicative of exploitation attempts. 5. Disable or restrict the PrintWorkflowUserSvc service where printing workflows are not critical or can be managed through alternative means. 6. Prepare for rapid deployment of official patches from Microsoft once available by maintaining an up-to-date asset inventory and patch management process. 7. Conduct user awareness training to reduce the risk of privilege escalation through social engineering that might precede exploitation. 8. Use network segmentation to limit the ability of an attacker to move laterally after local compromise.