Critical vulnerabilities have emerged within Windows Remote Desktop Clients (RDC), presenting significant cybersecurity risks for users worldwide. As of 2025, multiple critical remote code execution (RCE) vulnerabilities have been identified in both Windows RDC and Remote Desktop Services (RDS). These flaws possess high severity scores, with CVSS ratings reaching 8.1 and 8.8, indicating a serious risk of full system compromise.
Exploitation of these RCE vulnerabilities can occur through a malicious Remote Desktop Protocol (RDP) server or via a man-in-the-middle (MITM) attack, eliminating the necessity to exploit vulnerabilities on the server side. Successful attacks may lead to arbitrary code execution on the client machine, allowing attackers to gain a foothold on the network or seize complete control of the system. This scenario highlights the urgent necessity for users to apply security patches, which Microsoft regularly releases to mitigate such critical vulnerabilities. Patch Tuesday Updates have become crucial in addressing these vulnerabilities, emphasizing the need for timely patch management. Zero-day vulnerabilities can result in devastating financial losses when exploited before patches become available.
Exploiting RCE vulnerabilities allows attackers to execute arbitrary code, emphasizing the critical need for prompt security patch application.
Specific vulnerabilities noted include CVE-2025-29966 and CVE-2025-29967, which are buffer overflow flaws in the RDP client’s bitmap-compression routines. These flaws permit arbitrary code execution when processing oversized bitmap updates from RDP servers. Furthermore, CVE-2025-26645 impacts the Remote Desktop Client directly, further illustrating the breadth of these vulnerabilities as they can affect both client and server iterations of Windows Remote Desktop.
Attackers can access Windows machines merely by controlling an RDP server or by positioning themselves as MITM. The flaws are rooted in the client implementation, which broadens potential attack targets without requiring server exploitation. Such exploitation could lead not only to data theft but similarly to lateral movement within networks or deployment of malware and ransomware. Additionally, the active exploitation of six patched vulnerabilities highlights the ongoing threat landscape that users must navigate.
Microsoft strongly advises the urgent installation of relevant patches, whereas organizations should consider enhancing their security posture with monitoring for abnormal activities, enforcing multi-factor authentication, and implementing proactive network segmentation, all essential for users exposing RDP access.
