CVE-2026-42985

Microsoft · Remote Desktop Client

A heap-based buffer overflow in the Remote Desktop Client allows an unauthorized attacker to execute code over a network.

Executive summary

A critical heap-based buffer overflow in the Remote Desktop Client enables remote code execution, creating a significant risk of system-wide compromise.

Vulnerability

The vulnerability resides in the heap management of the Remote Desktop Client. An unauthenticated attacker can trigger a buffer overflow by sending specially crafted packets, potentially leading to arbitrary code execution within the security context of the user running the client.

Business impact

With a CVSS score of 8.8, the ability for an attacker to execute code remotely via a client-side overflow is severe. This could lead to complete workstation compromise, allowing the attacker to steal credentials, access sensitive corporate data, or pivot into the internal network.

Remediation

Immediate Action: Apply the latest security patches provided by Microsoft for the Remote Desktop Client application.

Proactive Monitoring: Monitor network traffic for unusual Remote Desktop Protocol (RDP) activity and investigate any unexpected system crashes occurring during RDP sessions.

Compensating Controls: Restrict RDP access to trusted networks and ensure that endpoints are protected by robust Endpoint Detection and Response (EDR) solutions.

Exploitation status

Public Exploit Available: false

Analyst recommendation

Given that Remote Desktop is a primary attack vector, this vulnerability must be treated with extreme urgency. IT teams should ensure all endpoints running the Remote Desktop Client are patched immediately to prevent potential remote exploitation.