CVE-2025-48805 is a high-severity heap-based buffer overflow vulnerability identified in the Microsoft MPEG-2 Video Extension component of Windows 10 Version 1809 (build 10.0.17763.0). This vulnerability arises due to improper handling of memory buffers on the heap when processing MPEG-2 video data, which can lead to memory corruption. An authorized attacker with local access and low privileges (PR:L) can exploit this flaw to execute arbitrary code on the affected system without requiring user interaction (UI:N). The vulnerability impacts confidentiality, integrity, and availability (C:H/I:H/A:H), allowing the attacker to potentially escalate privileges, execute malicious payloads, or cause system crashes. The CVSS v3.1 base score is 7.8, reflecting the significant risk posed by this vulnerability. No known exploits are currently reported in the wild, and no official patches or mitigations have been linked yet. The vulnerability was reserved in late May 2025 and published in early July 2025. Given the nature of the flaw, exploitation would typically require the attacker to have some level of access to the target system, such as through a compromised user account or local access scenario. The lack of required user interaction suggests that once local access is obtained, exploitation can be automated or triggered without further user involvement. This vulnerability is particularly concerning for environments where Windows 10 Version 1809 is still in use, especially in legacy or industrial systems that have not been updated to newer Windows versions. The MPEG-2 Video Extension is commonly used for media playback and processing, so systems that handle multimedia content are at risk. The heap-based buffer overflow (CWE-122) is a classic memory corruption issue that can be leveraged for code execution, making it a critical target for attackers aiming to gain persistence or elevate privileges on affected machines.

For European organizations, the impact of CVE-2025-48805 can be significant, especially in sectors relying on Windows 10 Version 1809 for operational continuity, such as manufacturing, healthcare, government, and critical infrastructure. Exploitation could lead to unauthorized code execution, allowing attackers to deploy malware, ransomware, or conduct espionage activities. The compromise of confidentiality could expose sensitive personal data protected under GDPR, leading to regulatory penalties and reputational damage. Integrity and availability impacts could disrupt business operations, causing downtime and financial losses. Since the vulnerability requires local access but no user interaction, insider threats or attackers who gain initial footholds through other means could leverage this flaw to escalate privileges or move laterally within networks. The absence of known exploits in the wild currently reduces immediate risk but does not eliminate it, as attackers may develop exploits rapidly once details are public. Organizations with legacy systems or those slow to patch are particularly vulnerable. The multimedia processing nature of the vulnerability means that systems used for video playback, conferencing, or media editing are at elevated risk, which is relevant for sectors like media, education, and public services.

1. Immediate mitigation should focus on upgrading affected systems to a supported and patched version of Windows, ideally moving away from Windows 10 Version 1809 to a more recent release with active security updates. 2. If upgrading is not immediately feasible, organizations should restrict local access to affected systems to trusted personnel only and enforce strict access controls and monitoring. 3. Disable or restrict the use of the Microsoft MPEG-2 Video Extension where possible, especially on systems that do not require multimedia processing capabilities. 4. Employ application whitelisting and endpoint detection and response (EDR) solutions to detect and prevent unauthorized code execution attempts. 5. Monitor system logs and security alerts for unusual behavior indicative of exploitation attempts, such as unexpected process launches or memory anomalies. 6. Implement network segmentation to limit lateral movement opportunities if a system is compromised. 7. Educate users and administrators about the risks of running outdated Windows versions and the importance of applying security updates promptly. 8. Prepare incident response plans specifically addressing local privilege escalation and code execution scenarios to enable rapid containment and remediation.