Microsoft Remote Desktop Client: Heap-based buffer overflow allows local code execution
Summary
A heap-based buffer overflow in the Microsoft Remote Desktop Client allows an attacker with a low-privileged local account to execute code on the affected Windows system. The CVSS score is 7.8 (High), with high impact on confidentiality, integrity and availability. The attack requires local access and a valid account, so it is not exploitable remotely over the network.
Affected
- Windows 10 Version 1607: 10.0.14393.0 before 10.0.14393.9688
- Windows 10 Version 1809: 10.0.17763.0 before 10.0.17763.9487
- Windows 10 Version 21H2: 10.0.19044.0 before 10.0.19044.7846
- Windows 10 Version 22H2: 10.0.19045.0 before 10.0.19045.7846
- Windows 11 Version 23H2: 10.0.22631.0 before 10.0.22631.7711
- Windows 11 Version 24H2: 10.0.26100.0 before 10.0.26100.9974
- Windows 11 Version 25H2: 10.0.26200.0 before 10.0.26200.9974
- Windows 11 Version 26H1: 10.0.28000.0 before 10.0.28000.3501
- Windows 11 Version 26H2: 10.0.26300.0 before 10.0.26300.9974
- Windows Server 2016 (including Server Core): 10.0.14393.0 before 10.0.14393.9688
- Windows Server 2019 (including Server Core): 10.0.17763.0 before 10.0.17763.9487
- Windows App Client for Windows Desktop: version list not confirmed
- Note: The version list is taken from the CVE record. Secondary sources list additional products and builds that are not confirmed by the vendor.
Fixed in
- Fixed in the Windows security updates released in November 2026.
- Fixed builds are the first builds at or above the build numbers listed under affected.
- Exact KB article numbers per build: Unknown. Check the MSRC advisory.
Workaround
- No vendor workaround known. Status: Unknown.
- Interim measure: restrict local interactive logon on shared or multi-user systems.
- Interim measure: limit who can use the RDP client on jump hosts and terminal servers until patched.
Exploitation
- Not known to be exploited in the wild.
- No public proof-of-concept exploit found.
- CISA SSVC: Exploitation none, Automatable no, Technical Impact total.
Our recommendation
- Install the November 2026 Windows security update on all affected systems in the regular patch cycle.
- Prioritise shared PCs, Remote Desktop Services or terminal servers, and RDP jump hosts.
- Restrict local logon to trusted users on multi-user systems.
- Recheck the MSRC advisory for the exact affected builds and KB numbers, and check NVD once analysis is complete.
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 less likely
- 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
- MSRC Security Update Guide: CVE-2026-119390 msrc.microsoft.com
- CVE Record: CVE-2026-119390 www.cve.org
- Strix.ai: CVE-2026-119390 www.strix.ai
- Rapid7: Patch Tuesday November 2026 www.rapid7.com
- Rescana: Patch Tuesday November 2026 summary rescana.com
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, 03:53.
Original description (NVD)
Heap-based buffer overflow in Remote Desktop Client allows an authorized attacker to execute code locally.
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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