Junglewise Threat Intelligence

CVE-2026-42985: Microsoft Remote Desktop Client heap overflow

CVE-2026-42985 · Severity: high · CVSS 8.8 · Published 2026-06-09

Technologies: Microsoft Remote Desktop Client. Vendors: Microsoft.

Executive brief

A vulnerability in the Microsoft Remote Desktop Client allows a remote attacker to execute malicious code on a user's computer. This occurs when a user connects to a malicious or compromised server, potentially leading to a full system takeover and theft of sensitive data. Organizations should ensure all remote desktop software is updated immediately to prevent unauthorized access.

Technical details

A heap-based buffer overflow vulnerability exists in the Microsoft Remote Desktop Client. The flaw is triggered when the client processes a specially crafted response from a malicious or compromised RDP server. While the attack vector is network-based, it requires user interaction (UI:R), meaning a user must be induced to connect to the attacker-controlled server. Successful exploitation allows for remote code execution (RCE) in the context of the logged-in user. Although the NVD description mentions a heap overflow, the Microsoft CWE classification also references CWE-416 (Use After Free), suggesting memory corruption during session handling.

Affected products

  • Microsoft Remote Desktop Client

Timeline

  • 2026-06-09: advisory: Initial advisory published by Microsoft and NVD.

References

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