CVE-2025-55690 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). Use-after-free vulnerabilities occur when a program continues to use a pointer after the memory it points to has been freed, leading to undefined behavior including memory corruption. In this case, an authorized local attacker can exploit this flaw to elevate their privileges on the affected system. The vulnerability requires local access and has a high attack complexity, meaning it is not trivial to exploit but feasible under certain conditions. No user interaction is required, which increases the risk once local access is obtained. The CVSS v3.1 base score is 7.0, reflecting high impact on confidentiality, integrity, and availability, but mitigated somewhat by the need for local privileges and high complexity. The flaw resides in the PrintWorkflowUserSvc, a Windows service related to print workflow management, which may be targeted to gain elevated privileges and potentially execute arbitrary code or disable security controls. Although no exploits are known in the wild and no patches have been released yet, the vulnerability is publicly disclosed and should be addressed promptly. This vulnerability is significant because Windows 11 25H2 is a current and widely used operating system version, especially in enterprise environments. Attackers gaining elevated privileges can move laterally, install persistent malware, or exfiltrate sensitive data.

For European organizations, this vulnerability poses a significant risk due to the widespread deployment of Windows 11 Version 25H2 in corporate and government environments. Successful exploitation could allow attackers with local access—such as malicious insiders or attackers who have compromised lower-privileged accounts—to escalate privileges to SYSTEM or administrative levels. This elevation could lead to full system compromise, data breaches, disruption of critical services, and potential lateral movement within networks. Sectors such as finance, healthcare, government, and critical infrastructure are particularly vulnerable due to the sensitivity and criticality of their data and operations. The lack of known exploits currently reduces immediate risk, but the public disclosure increases the likelihood of future exploit development. The absence of a patch means organizations must rely on interim mitigations, increasing operational complexity and risk exposure. Additionally, the vulnerability could be leveraged in targeted attacks against high-value European targets, potentially impacting national security and economic stability.

1. Restrict local access: Limit the number of users with local access to systems running Windows 11 Version 25H2, especially those with low privileges that could attempt privilege escalation. 2. Apply principle of least privilege: Ensure users and processes operate with the minimum privileges necessary to reduce the attack surface. 3. Monitor PrintWorkflowUserSvc activity: Implement enhanced logging and monitoring for unusual or unauthorized activity related to the PrintWorkflowUserSvc service. 4. Use application whitelisting and endpoint detection and response (EDR) tools to detect and block suspicious behaviors indicative of exploitation attempts. 5. Prepare for patch deployment: Stay alert for official patches from Microsoft and plan rapid deployment once available to remediate the vulnerability. 6. Conduct regular vulnerability assessments and penetration testing focusing on privilege escalation vectors. 7. Educate IT staff and users about the risks of local privilege escalation and enforce strong local account management policies. 8. Consider network segmentation to limit lateral movement opportunities if an endpoint is compromised.