Microsoft Remote Desktop Client: Remote code execution via race condition
Summary
The Remote Desktop Client for Windows contains a race condition (CWE-362) caused by improper synchronization of a shared resource. An unauthorized attacker can execute code on an affected system over the network, which can impact confidentiality, integrity and availability. According to the CVSS vector, exploitation requires high attack complexity and user interaction, for example a user connecting to an attacker-controlled RDP host.
Affected
- Windows 10 Version 1607 and Windows Server 2016 (including Server Core): builds before 10.0.14393.9688
- Windows 10 Version 1809 and Windows Server 2019 (including Server Core): builds before 10.0.17763.9487
- Windows 10 Version 21H2: builds before 10.0.19044.7846
- Windows 10 Version 22H2: builds before 10.0.19045.7846
- Windows 11 Version 23H2: builds before 10.0.22631.7711
- Windows 11 Version 24H2: builds before 10.0.26100.9974
- Windows 11 Version 25H2 and 26H2: builds before 10.0.26200.9974 and 10.0.26300.9974
- Windows 11 Version 26H1: builds before 10.0.28000.3501
- Windows Server 2022: builds before 10.0.20348.5870
Fixed in
- Install the November 2026 Windows security update for your version. The build numbers above are the first fixed builds according to the official CVE record.
- Confirm the fixed build and the matching KB article on the MSRC advisory before rollout.
Workaround
- No vendor workaround known.
- Avoid connecting to unknown or untrusted RDP hosts.
- Do not open .rdp files from unverified emails or links.
- Restrict outbound RDP connections where business processes allow.
Exploitation
- Exploited in the wild: Unknown. No source confirms exploitation of this CVE.
- CISA SSVC: Exploitation none, not automatable, total technical impact.
- Public proof of concept: Unknown.
Our recommendation
- Deploy the November 2026 Windows updates to all Windows clients and servers running the Remote Desktop Client, with priority on endpoints that often connect to external RDP hosts.
- Verify the fixed builds on the MSRC advisory.
- Train staff not to connect to unknown RDP sessions or open unexpected .rdp files.
- Monitor for unusual outbound RDP connections.
Information from Microsoft (Patch Tuesday November 2026)
- Severity (Microsoft)
- Important
- Impact
- Remote code execution – Remote Desktop Client
- Status on Patch Tuesday
- Neither exploited nor publicly disclosed
- Exploitability assessment
- Exploitation unlikely
- Product family
- Windows, Windows ESU (Extended Security Updates)
- Updates (KB)
- KB5131291, KB5131085, KB5131096, KB5131090, KB5131087, KB5132061
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Microsoft Security Update Guide: CVE-2026-95964 msrc.microsoft.com
- CVE Record CVE-2026-95964 www.cve.org
- Rapid7: Patch Tuesday November 2026 www.rapid7.com
- ZDI: November 2026 Security Update Review www.thezdi.com
- Action1: Patch Tuesday November 2026 www.action1.com
- Strix: CVE-2026-95964 www.strix.ai
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 11 Nov 2026, 05:05.
Original description (NVD)
Concurrent execution using shared resource with improper synchronization ('race condition') in Remote Desktop Client allows an unauthorized attacker to execute code over a network.
NVD references (1)
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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