CVE-2026-42909: Remote Desktop Client Remote Code Execution Vulnerability
Concurrent execution using shared resource with improper synchronization ('race condition') in Remote Desktop Client allows an unauthorized attacker to execute code over a network.
Other sources
Heap-based buffer overflow in Remote Desktop Client allows an unauthorized attacker to execute code over a network.
— Microsoft
Remote Desktop Client Remote Code Execution Vulnerability
— Microsoft
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.14393.9234Patch KB5094122 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.28000.2269Patch KB5095051 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.26100.8655Patch KB5094126 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.26100.32995Patch KB5094125 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.22631.7219Patch KB5093998 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.26200.8655Patch KB5094126 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.19045.7417Patch KB5094127 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.19044.7417Patch KB5094127 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 1.2.7214.0 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.20348.5256Patch KB5094128 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 2.0.1193.0 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.17763.8880Patch KB5094123 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 6.3.9600.23228Patch KB5094041 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 6.2.9200.26132Patch KB5094042
Event History
Frequently Asked Questions
What is the severity of CVE-2026-42909?
The severity of CVE-2026-42909 is rated as high, with a score of 7.5.
What does CVE-2026-42909 affect?
CVE-2026-42909 affects multiple versions of Microsoft Windows, including Windows 10, Windows 11, and various versions of Windows Server.
How do I fix CVE-2026-42909?
To fix CVE-2026-42909, you should apply the latest security updates provided by Microsoft for your Windows operating system.
What type of vulnerability is CVE-2026-42909?
CVE-2026-42909 is a Remote Code Execution vulnerability caused by a heap-based buffer overflow in the Remote Desktop Client.
Who is at risk from CVE-2026-42909?
Any unauthorized attacker with network access could exploit CVE-2026-42909 to execute arbitrary code on vulnerable systems.