CVE-2026-97789 in Windows
Summary
by MITRE • 10/15/2026
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 • 10/15/2026
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 reference a memory block after it has been freed or deallocated by the system. In the context of client-side applications like Remote Desktop Connection (mstsc.exe), this often occurs during the processing of complex RDP packets or specific control structures that trigger dynamic allocation and subsequent release of resources. When an attacker crafts malicious network traffic designed to exploit this timing window, they can manipulate the freed memory region before it is reallocated for legitimate purposes, thereby gaining arbitrary write capabilities within the process address space.
From a technical perspective, use-after-free vulnerabilities are particularly dangerous because they allow attackers to overwrite function pointers or object vtables with controlled data structures. By carefully constructing the payload sent over the network, an unauthorized actor can redirect execution flow to shellcode injected into the same memory region. This effectively bypasses standard security mitigations such as Data Execution Prevention (DEP) and Address Space Layout Randomization (ASLR), provided the attacker has sufficient control over heap layout or utilizes specific exploitation techniques like heap spraying or partial overwrite attacks. The impact is severe, granting the attacker full administrative privileges on the compromised host system without requiring any user interaction beyond initiating a connection to the malicious server or processing a specially crafted file if saved locally.
This vulnerability aligns with Common Weakness Enumeration (CWE) identifier CWE-416, which defines use-after-free conditions as a result of using memory after it has been freed. In terms of offensive security frameworks, this exploit path corresponds directly to the MITRE ATT&CK technique T1203, specifically sub-technique 1203.2 for exploitation via client-side software. The attack vector is classified as Network (Attack Vector: N) with High complexity and requires no user privileges on the target system other than network connectivity, making it a high-severity remote code execution risk. Organizations relying on Remote Desktop services are particularly exposed if these clients are updated to versions containing this flaw but not yet patched against the specific memory corruption trigger.
Mitigation strategies must prioritize immediate patching of all affected Microsoft Windows operating systems and Remote Desktop Client installations using official security updates provided by the vendor. Until patches are applied, administrators should restrict access to RDP services through strict firewall rules, limiting inbound connections only from trusted IP addresses or virtual private networks (VPNs). Additionally, enabling Network Level Authentication (NLA) can provide an additional layer of defense by requiring authentication before a full session is established, potentially blocking some exploit attempts that rely on specific client-side processing stages. Security teams should also monitor for anomalous network traffic patterns indicative of RDP exploitation attempts and ensure endpoint detection and response solutions are updated to recognize signatures associated with this memory corruption vulnerability.