Summary
Impact: Remote Code Execution. Microsoft rating: Important. Not known to be exploited — Exploitation Less Likely. Customer action: Required.
Details
According to the CVSS metric, the attack complexity is high (AC:H). What does that mean for this vulnerability?
Successful exploitation of this vulnerability requires an attacker to take additional actions prior to exploitation to prepare the target environment.
How could an attacker exploit this vulnerability?
In the case of a Remote Desktop connection, an attacker with control of a Remote Desktop Server could trigger a remote code execution (RCE) on the machine when a victim connects to the attacking server with the vulnerable Remote Desktop Client.
Security updates
10.0.20348.5256 — https://support.microsoft.com/help/5094128
10.0.19044.7417 — https://support.microsoft.com/help/5094127
10.0.26100.32995 — https://support.microsoft.com/help/5094125
10.0.26200.8655 — https://support.microsoft.com/help/5094126
10.0.22631.7219 — https://support.microsoft.com/help/5093998
10.0.28000.2269 — https://support.microsoft.com/help/5095051
Vulnerabilities 1
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High 7.5
Remote Desktop Client Remote Code Execution Vulnerability
Heap-based buffer overflow in Remote Desktop Client allows an unauthorized attacker to execute code over a network.
Revision history
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#2
Updated an acknowledgement. This is an informational change only.
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#1
Information published.
References
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CVE-2026-42993 Remote Desktop Client Remote Code Execution Vulnerability - HTML
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-42993
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Microsoft Exploitability Index
https://www.microsoft.com/en-us/msrc/exploitability-index?rtc=1
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Microsoft Support Lifecycle
https://support.microsoft.com/lifecycle
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Common Vulnerability Scoring System
https://www.first.org/cvss