CVE-2025-53149 is a heap-based buffer overflow vulnerability identified in the Kernel Streaming WOW Thunk Service Driver component of Microsoft Windows 10 Version 1809 (build 10.0.17763.0). This vulnerability arises due to improper handling of memory buffers in kernel mode, specifically within the streaming service driver that facilitates audio and video data processing. An authorized local attacker with limited privileges can exploit this flaw by triggering a carefully crafted input that causes a heap buffer overflow, leading to memory corruption. This corruption can be leveraged to execute arbitrary code with elevated privileges, effectively allowing privilege escalation from a lower-privileged user context to SYSTEM-level access. The vulnerability does not require user interaction but does require local access with some privileges (PR:L). The CVSS v3.1 base score is 7.8, reflecting high severity, with high impact on confidentiality, integrity, and availability (C:H/I:H/A:H). No known exploits are currently reported in the wild, and no official patches have been linked yet. The vulnerability was reserved in late June 2025 and published in August 2025. The lack of a patch at this time increases the risk for unpatched systems. Given the kernel-level nature of the flaw, exploitation could allow attackers to bypass security controls, install persistent malware, or disrupt system operations.

For European organizations, this vulnerability poses a significant risk, especially for enterprises and government agencies still operating legacy Windows 10 Version 1809 systems. Successful exploitation could lead to full system compromise, data breaches, and disruption of critical services. Organizations in sectors such as finance, healthcare, and critical infrastructure could face severe confidentiality and integrity losses, as attackers could gain SYSTEM privileges and access sensitive information or deploy ransomware. The local attack vector means that insider threats or attackers who gain initial foothold via other means (e.g., phishing leading to limited user access) could escalate privileges to control entire systems. The absence of a patch increases exposure, and organizations relying on this Windows version must prioritize risk assessment and mitigation. Additionally, compliance with GDPR and other European data protection regulations could be jeopardized if breaches occur due to this vulnerability.

1. Immediate mitigation should focus on identifying and isolating systems running Windows 10 Version 1809 (build 17763.0) to assess exposure. 2. Restrict local user privileges strictly, minimizing the number of users with any elevated or local access rights to reduce the attack surface. 3. Employ application whitelisting and endpoint detection and response (EDR) solutions to monitor for suspicious behavior indicative of privilege escalation attempts. 4. Implement strict network segmentation to limit lateral movement from compromised accounts. 5. Until an official patch is released, consider disabling or restricting the Kernel Streaming WOW Thunk Service Driver if feasible, or applying system hardening techniques to reduce attack vectors. 6. Enforce multi-factor authentication (MFA) for all user accounts to reduce the risk of initial compromise. 7. Maintain up-to-date backups and test recovery procedures to mitigate impact of potential exploitation. 8. Monitor threat intelligence feeds for updates on exploit availability and patch releases to respond promptly.