CVE-2025-55698 is a vulnerability classified under CWE-476 (NULL Pointer Dereference) affecting Microsoft Windows 11 Version 25H2 (build 10.0.26200.0). The flaw exists within the DirectX component, a core multimedia API used for rendering graphics and handling multimedia tasks. The vulnerability allows an authorized attacker with low privileges to remotely trigger a null pointer dereference, causing the system or affected service to crash, resulting in a denial of service (DoS). The attack vector is network-based (AV:N), requiring low attack complexity (AC:L) and only low privileges (PR:L), but no user interaction (UI:N). The scope is changed (S:C), meaning the vulnerability can affect resources beyond the initially compromised component. The CVSS v3.1 base score is 7.7, indicating high severity primarily due to the impact on availability (A:H) without affecting confidentiality or integrity. The vulnerability was reserved in August 2025 and published in October 2025, with no known exploits in the wild yet. DirectX’s role in multimedia and gaming means that systems running Windows 11 25H2 with network-exposed multimedia services or remote desktop capabilities could be targeted. The lack of patches at the time of reporting means organizations must rely on interim mitigations until official updates are released.

For European organizations, the primary impact is the potential for denial of service attacks that could disrupt critical business operations, especially in sectors relying heavily on Windows 11 25H2 for multimedia processing, remote desktop services, or networked applications utilizing DirectX. This could affect service availability in industries such as finance, healthcare, manufacturing, and government services. The disruption could lead to operational downtime, loss of productivity, and potential reputational damage. Since the vulnerability requires only low privileges and no user interaction, attackers could exploit it remotely, increasing the risk of widespread impact. Organizations with network-exposed Windows 11 endpoints or remote access infrastructure are particularly vulnerable. The absence of confidentiality or integrity impact reduces risks of data breaches but does not diminish the operational threat posed by service outages.

1. Monitor Microsoft security advisories closely and apply official patches for Windows 11 Version 25H2 as soon as they become available to remediate the vulnerability. 2. Until patches are released, restrict network access to systems running the vulnerable Windows version, especially limiting exposure of DirectX-related services and remote desktop protocols. 3. Employ network segmentation and firewall rules to minimize attack surface and prevent unauthorized access to critical endpoints. 4. Use intrusion detection and prevention systems (IDS/IPS) to detect anomalous traffic patterns that may indicate exploitation attempts targeting DirectX components. 5. Enforce least privilege principles to reduce the number of users with the required privileges to exploit this vulnerability. 6. Conduct regular system and application monitoring to quickly identify crashes or service disruptions indicative of exploitation. 7. Educate IT staff about this vulnerability to ensure rapid response and mitigation implementation.