CVE-2025-55690 is a use-after-free vulnerability classified under CWE-416, found in the Windows PrintWorkflowUserSvc service on Windows 11 Version 25H2 (build 10.0.26200.0). This vulnerability occurs when the service improperly manages memory, freeing an object while it is still in use, which can lead to memory corruption. An authorized attacker with low privileges on the local machine can exploit this flaw to execute arbitrary code with elevated privileges, effectively escalating their rights to higher privilege levels such as SYSTEM. The attack complexity is high, requiring detailed knowledge of the system and the vulnerability, but no user interaction is needed once local access is obtained. The vulnerability affects confidentiality, integrity, and availability by allowing attackers to bypass security controls, manipulate system processes, and potentially disrupt services. Although no known exploits are currently in the wild, the severity and potential impact make it a significant threat. The lack of an available patch at the time of disclosure necessitates immediate mitigation efforts. The vulnerability is particularly relevant for environments where local user accounts have limited restrictions or where printing workflows are critical to business operations. The CVSS v3.1 score of 7.0 reflects the high severity, considering the local attack vector, required privileges, and potential for full system compromise.

For European organizations, this vulnerability poses a substantial risk as Windows 11 adoption continues to grow across enterprises and public sector entities. The ability for a low-privileged local user to escalate privileges can lead to unauthorized access to sensitive data, disruption of critical printing services, and broader system compromise. This is especially concerning in regulated industries such as finance, healthcare, and government, where data confidentiality and system integrity are paramount. The vulnerability could be leveraged by insider threats or attackers who gain initial foothold through other means, enabling lateral movement and persistence within networks. The absence of a patch increases the window of exposure, potentially allowing attackers to develop exploits. Organizations relying on print workflows for document processing and compliance may experience operational disruptions. Additionally, the vulnerability could be chained with other exploits to achieve remote code execution or broader network compromise, amplifying its impact.

Given the lack of an official patch, European organizations should implement strict local access controls to limit the number of users with local login capabilities, especially on systems running Windows 11 Version 25H2. Employ application whitelisting and endpoint detection and response (EDR) solutions to monitor and block suspicious activities related to PrintWorkflowUserSvc. Disable or restrict the PrintWorkflowUserSvc service where printing workflows are not essential or can be temporarily suspended. Conduct thorough audits of local user privileges and remove unnecessary administrative rights. Implement network segmentation to isolate critical systems and reduce the risk of lateral movement. Maintain up-to-date backups and ensure incident response plans include scenarios involving privilege escalation. Monitor security advisories closely for patch releases and apply them promptly once available. Educate IT staff about this vulnerability to recognize potential exploitation attempts. Consider deploying enhanced logging and alerting on printing service activities to detect anomalies early.