CVE-2025-53805 is a high-severity vulnerability identified in Microsoft Windows Server 2022, specifically affecting the Windows Internet Information Services (IIS) component. The vulnerability is classified as an out-of-bounds read (CWE-125), which occurs when the software reads data outside the boundaries of allocated memory. This flaw can be triggered remotely over the network without requiring any authentication or user interaction, making it particularly dangerous. Exploiting this vulnerability allows an unauthorized attacker to cause a denial of service (DoS) condition by crashing the IIS service or the entire server, thereby disrupting availability. The CVSS v3.1 base score of 7.5 reflects the high impact on availability (A:H) while confidentiality and integrity remain unaffected (C:N/I:N). The attack vector is network-based (AV:N), with low attack complexity (AC:L), and no privileges or user interaction required (PR:N/UI:N). Although no known exploits are currently reported in the wild, the vulnerability’s characteristics suggest it could be weaponized to disrupt critical web services hosted on Windows Server 2022. The affected version is 10.0.20348.0, and no official patches or mitigations have been published yet, increasing the urgency for organizations to monitor updates closely and implement interim protective measures. Given IIS’s widespread use in enterprise environments, this vulnerability poses a significant risk to service availability and operational continuity.

For European organizations, the impact of CVE-2025-53805 could be substantial, especially for those relying on Windows Server 2022 to host web applications, intranet portals, or critical business services via IIS. A successful exploitation would result in denial of service, leading to downtime, loss of productivity, and potential financial losses. Sectors such as finance, healthcare, government, and telecommunications, which often depend on IIS for internal and external-facing services, would be particularly vulnerable. Disruption of these services could also affect compliance with regulatory requirements around service availability and incident response. Additionally, the lack of confidentiality or integrity impact means data breaches are unlikely, but the availability impact alone can cause cascading effects in interconnected systems and supply chains. The vulnerability’s network-based exploitation vector increases the risk of automated attacks or scanning by malicious actors targeting exposed IIS servers across Europe.

Given the absence of an official patch at this time, European organizations should implement several specific mitigations: 1) Restrict network access to IIS servers by implementing strict firewall rules and network segmentation to limit exposure only to trusted IP addresses and necessary services. 2) Employ Web Application Firewalls (WAFs) capable of detecting anomalous requests or malformed packets that could trigger out-of-bounds reads. 3) Monitor IIS server logs and network traffic for unusual patterns or repeated crashes that may indicate exploitation attempts. 4) Implement robust incident response plans to quickly isolate and recover affected systems in case of a DoS event. 5) Prioritize patch management to deploy official updates from Microsoft immediately upon release. 6) Consider temporary alternatives or load balancing to reduce the impact of potential service disruptions. 7) Conduct internal vulnerability scanning and penetration testing focused on IIS to proactively identify and mitigate related risks.