CVE-2025-55684 is a use-after-free vulnerability classified under CWE-416, affecting the Windows PrintWorkflowUserSvc service in Microsoft Windows 11 Version 25H2 (build 10.0.26200.0). The vulnerability occurs 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 a higher level, potentially SYSTEM or administrator. The vulnerability does not require user interaction but has a high attack complexity, meaning exploitation demands specific conditions or expertise. The CVSS v3.1 score is 7.0, reflecting high impact on confidentiality, integrity, and availability, but limited by the need for local access and complex exploitation. No public exploits have been reported yet, and no patches are currently linked, indicating that remediation is pending. The flaw resides in a critical Windows service responsible for print workflow management, which is commonly enabled in enterprise environments. Successful exploitation could allow attackers to bypass security controls, execute malicious code with elevated privileges, and compromise system integrity and data confidentiality.

For European organizations, this vulnerability poses a significant risk, especially in sectors relying heavily on Windows 11 25H2, such as government, finance, healthcare, and critical infrastructure. Privilege escalation vulnerabilities can enable attackers to gain administrative control, facilitating further lateral movement, data exfiltration, or deployment of ransomware. The PrintWorkflowUserSvc is often active in environments with printing services, which are common in office and industrial settings. Exploitation could disrupt printing workflows, degrade system availability, and compromise sensitive documents. Given the high confidentiality, integrity, and availability impact, organizations could face operational disruptions, data breaches, and compliance violations under GDPR. The lack of known exploits currently provides a window for proactive mitigation, but the presence of this vulnerability in a widely deployed OS version means that threat actors may develop exploits rapidly.

Organizations should prioritize monitoring and restricting access to the PrintWorkflowUserSvc service, limiting it to trusted users only. Implement application whitelisting and endpoint detection and response (EDR) solutions to detect anomalous behavior indicative of privilege escalation attempts. Since no official patch is currently available, consider applying temporary workarounds such as disabling or restricting the PrintWorkflowUserSvc if printing workflows allow. Employ strict local user privilege management to minimize the number of users with local access rights. Conduct regular system audits to identify unauthorized changes or suspicious activity. Prepare to deploy patches promptly once Microsoft releases them. Additionally, educate IT staff about this vulnerability to ensure rapid response and containment. Network segmentation can also reduce the risk of lateral movement if exploitation occurs.