Security of on-premises infrastructures remains a critical challenge for organizations managing legacy or hybrid environments. Recently, the U.S. Cybersecurity and Infrastructure Security Agency (CISA) issued an alert about the active exploitation of several vulnerabilities in Microsoft SharePoint Server, urging immediate hardening measures. This incident highlights the need for robust cybersecurity strategies, where early detection and responsiveness are as important as prevention. For businesses that still rely on in-house servers, understanding the scope of these threats and adopting modern tools — such as AWS and Azure cloud services — can make the difference between a minor incident and a major breach.
The reported vulnerabilities affect all supported versions of SharePoint Server on-premises, including Subscription Edition, 2019, and 2016. Attackers can achieve remote code execution (RCE) and, after exploiting the system, steal Internet Information Services (IIS) machine keys for persistence and deploy malware. These attacks typically employ deserialization techniques, a method that allows cybercriminals to manipulate serialized data and execute arbitrary commands. The CISA alert details not only the vulnerabilities already exploited (CVE-2026-32201, CVE-2026-45659, CVE-2026-56164), but also others that, although not yet exploited, pose a potential risk if not patched in time.
Faced with this scenario, organizations must act quickly. The first line of defense is to apply official security patches, verify their correct installation and shorten update cycles. But the protection doesn't end there. CISA recommends enabling the integration of the Anti-Malware Analysis Interface (AMSI) in each SharePoint web application, configuring the full request body scanning mode when possible. This integration allows you to detect specific signatures of exploits, such as those that attempt to bypass Tool Panel authentication or perform RCE. Additionally, it is crucial to review Microsoft Defender Antivirus (MDAV) detections for post-exploitation activities, such as stealing IIS-protected secrets.
Hardening must go beyond upgrades. Changing IIS machine keys without first looking for intrusion artifacts—such as key harvesters—can be counterproductive, as attackers could steal them again. Implementing custom logging mechanisms and reviewing telemetry for anomalous requests, suspicious SharePoint worker process activity, webshells, or improper key access is critical. CISA also advises against exposing SharePoint Server directly to the internet; If necessary, you should go after a Layer 7 reverse proxy that requires authentication and can inspect requests. Blocking external access to SharePoint central management and restricting farm and database communications are additional measures that reduce the attack surface.
This incident underscores a reality: cybersecurity is not a product that is installed and forgotten, but a continuous process of improvement. Organizations that lack specialized in-house teams or are looking to optimize their resources find an effective solution in technology partners. At Q2BSTUDIO we offer cybersecurity and pentesting services that help identify vulnerabilities before attackers do, evaluating both on-premises and cloud environments. Our team performs extensive penetration testing, reviews SharePoint configurations, and proposes customized remediation plans. If your company still manages its own servers, migrating partially or fully to AWS and Azure cloud services not only reduces the operational burden, but also shifts some of the security responsibility to providers with dedicated teams. At Q2BSTUDIO we accompany this process with IT security and auditing solutions that guarantee a secure transition.
Beyond SharePoint, the lessons in this alert apply to any business application that handles sensitive data. Artificial intelligence for businesses can play a key role in detecting anomalies: AI agents trained with normal traffic patterns can identify unusual behavior in real-time. Combined with business intelligence tools such as Power BI, it is possible to visualize and correlate security events from different sources, accelerating incident response. At Q2BSTUDIO we develop custom applications that integrate these components, creating customized dashboards for cybersecurity monitoring. In addition, our business intelligence services offering enables you to transform log data into actionable insights, helping IT teams prioritize risks and optimize resources.
Process automation is also an ally in the fight against vulnerabilities. Orchestration tools can programmatically apply patches, check AMSI status, and rotate machine keys without manual intervention. At Q2BSTUDIO we design tailor-made software solutions that are tailored to the specific needs of each client, whether it is to manage server fleets, implement secure backups in the cloud or deploy intrusion detection systems. Our team of AWS and Azure cloud service experts ensures that infrastructure is configured following security best practices, including network segmentation, encryption at rest and in transit, and role-based access.
All in all, CISA's alert on SharePoint is a reminder that no platform is immune. The combination of timely patching, secure configuration, continuous monitoring, and a comprehensive cybersecurity strategy is the only way to keep attackers at bay. Companies that invest in technologies such as artificial intelligence, AI agents, and power bi not only improve their security posture, but also gain in efficiency and adaptability. At Q2BSTUDIO we are committed to helping organizations protect themselves by offering software development, cybersecurity and cloud services that cover the entire IT security lifecycle. If you would like to assess the security of your SharePoint or explore how to migrate to a more robust environment, please contact us. Prevention is never an expense, but an investment in the continuity of your business.
