CVE-2026-103575 in Windows
Summary
by MITRE • 10/13/2026
Use after free in Remote Desktop Client allows an unauthorized attacker to execute code over a network.
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Analysis
by VulDB Data Team • 10/14/2026
The vulnerability described constitutes a critical security flaw within the Microsoft Remote Desktop Client, specifically categorized as a use-after-free error that enables remote code execution via network interaction. This type of defect arises from improper memory management practices where the application continues to access and utilize a pointer after the memory it references has been reallocated or freed by the system. In the context of the Remote Desktop Protocol (RDP) client, this flaw is triggered when processing specially crafted packets received over the network. An attacker who can interact with the vulnerable service does not need local authentication; instead, they can exploit this condition remotely to gain unauthorized access and execute arbitrary code on the target machine.
From a technical perspective, use-after-free vulnerabilities are among the most dangerous classes of memory corruption bugs because they allow an attacker to manipulate how the program interprets data in memory after it has been released back to the heap manager. When the Remote Desktop Client processes maliciously formatted RDP packets, it may free certain internal structures but retain references to them for subsequent operations. By carefully crafting network traffic that forces the application to access these dangling pointers before they are overwritten or reused by other system components, an attacker can control what data is read or written. This manipulation often leads to arbitrary code execution because the attacker can redirect program flow to shellcode injected into the memory space, effectively taking full control of the affected system.
The operational impact of this vulnerability is severe due to its remote nature and high privilege level upon successful exploitation. Since the flaw exists in a network-facing component used for administrative access, it presents an attractive attack vector for threat actors seeking to compromise critical infrastructure or enterprise environments without physical presence. Successful exploitation allows an attacker to run programs, install malware, create new accounts with full user rights, or modify and delete data. This effectively compromises the confidentiality, integrity, and availability of the affected system, potentially serving as a foothold for lateral movement within a network segment.
In terms of industry classification standards, this vulnerability aligns closely with CWE-416, which defines use-after-free conditions where pointers are used after they have been freed. It also maps to MITRE ATT&CK techniques related to remote code execution and exploitation of application vulnerabilities, specifically highlighting the potential for initial access through network services that lack proper input validation or memory safety checks. The exploitability is heightened by the fact that RDP is a commonly enabled service in Windows environments, increasing the attack surface significantly if not properly secured.
Mitigation strategies must focus on both immediate remediation and long-term architectural improvements. The primary defense involves applying vendor-provided security patches that address the underlying memory management logic within the Remote Desktop Client binaries. Organizations should prioritize patching all internet-facing or internal systems running vulnerable versions of Windows to eliminate this attack vector entirely. Additionally, implementing network segmentation can limit exposure by restricting RDP traffic to trusted subnets only. Enabling Network Level Authentication adds an extra layer of security by requiring authentication before a full connection is established, though it does not fully mitigate vulnerabilities present in the client software itself during session handling. Regular vulnerability scanning and monitoring for anomalous network activity related to RDP connections are also recommended to detect potential exploitation attempts early.