CVE-2025-55684 is a use-after-free vulnerability classified under CWE-416 found in the Windows PrintWorkflowUserSvc service in 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 arbitrary code execution or privilege escalation. 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 full control over the affected system. The attack complexity is high, requiring detailed knowledge of the system and the ability to execute code locally, but no user interaction is needed. The vulnerability impacts confidentiality, integrity, and availability by allowing attackers to bypass security controls and execute malicious code with elevated privileges. Although no public exploits have been reported yet, the vulnerability is rated with a CVSS v3.1 score of 7.0, indicating high severity. The flaw specifically targets the PrintWorkflowUserSvc, a service related to print workflow management, which is a critical component in Windows 11 for handling print jobs and workflows. The vulnerability was reserved in August 2025 and published in October 2025, with no patches currently available, emphasizing the need for proactive mitigation. Organizations should monitor for any suspicious activity related to this service and restrict local access to trusted users only.

For European organizations, this vulnerability poses a significant risk due to the widespread adoption of Windows 11 in enterprise environments. Successful exploitation can lead to local privilege escalation, allowing attackers to gain administrative control over affected systems. This can result in unauthorized access to sensitive data, disruption of business operations, installation of persistent malware, and lateral movement within networks. Critical sectors such as finance, healthcare, government, and industrial control systems that rely heavily on Windows 11 could face severe operational and reputational damage. The vulnerability's requirement for local access limits remote exploitation but increases the risk from insider threats or attackers who have already compromised lower-privileged accounts. The absence of a patch at the time of disclosure increases the window of exposure, making timely mitigation essential. Additionally, the PrintWorkflowUserSvc service is integral to print management, so exploitation could also disrupt printing services, impacting business continuity.

1. Restrict local access to the PrintWorkflowUserSvc service by applying strict access control lists (ACLs) and limiting service permissions to only essential users and processes. 2. Implement application whitelisting and endpoint detection and response (EDR) solutions to monitor and block suspicious activities related to privilege escalation attempts. 3. Enforce the principle of least privilege for all user accounts to minimize the impact of potential exploitation. 4. Monitor system logs and audit events for unusual behavior involving the PrintWorkflowUserSvc or unexpected privilege escalations. 5. Disable or restrict the PrintWorkflowUserSvc service on systems where printing workflows are not required or can be managed differently. 6. Prepare for rapid deployment of official patches from Microsoft once released, including testing in controlled environments before widespread rollout. 7. Educate IT staff and users about the risks of local privilege escalation vulnerabilities and the importance of maintaining strict endpoint security hygiene. 8. Consider network segmentation to isolate critical systems and reduce the risk of lateral movement following exploitation.