Windows Remote Desktop Client: Remote code execution through use-after-free
Summary
A use-after-free flaw (CWE-416) in the Remote Desktop Client of Windows allows code execution over the network. According to the NVD record, attack complexity is high and user interaction is required. An attacker who succeeds could compromise confidentiality, integrity and availability of the affected system. The sources do not describe the exact trigger scenario, and exposing an RDP server to the internet does not by itself create this flaw.
Affected
- Windows 10 Version 1607 and Windows Server 2016: before 10.0.14393.9612
- Windows 10 Version 1809: before 10.0.17763.9376
- Windows 10 Version 21H2: before 10.0.19044.7807
- Windows 10 Version 22H2: before 10.0.19045.7807
- Windows 11 Version 23H2: before 10.0.22631.7652
- Windows 11 Version 24H2: before 10.0.26100.9711
- Windows 11 Version 25H2: before 10.0.26200.9711
- Windows 11 Version 26H1: before 10.0.28000.3231
- Windows 11 Version 26H2: before 10.0.26300.9711
- Windows Server 2012 (including Server Core): before 6.2.9200.26434
- Windows Server 2012 R2 (including Server Core): before 6.3.9600.23470
Fixed in
Fixed builds are listed in the official CNA record for each version. Verify the exact builds on the MSRC Security Update Guide before rollout, as third-party sources differ for some Windows 11 versions.
For Windows 10 1607 and other systems without a listed fix, check MSRC for the support or Extended Security Updates status.
Workaround
Unknown.
Exploitation
- No known exploitation in the wild found in the sources. CISA SSVC data in the NVD record shows Exploitation: none and Automatable: no.
- No public proof-of-concept exploit found.
- VulDB estimates a possible exploit market price of USD 5k to 25k. This is an estimate, not evidence of use.
Our recommendation
- Patch all affected Windows clients and servers with the October 2026 security updates, starting with Windows 10 1607 and 1809 systems.
- Identify systems that are still on unsupported versions and plan upgrades or ESU enrolment.
- Check that the Remote Desktop Client is only used where needed and monitor for unusual crashes or code execution on client machines.
Information from Microsoft (Patch Tuesday October 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)
- KB5127648, KB5126651, KB5126655, KB5126657, KB5126646, KB5126653
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Microsoft Security Update Guide: CVE-2026-70012 msrc.microsoft.com
- Vulners: CNA data for CVE-2026-70012 vulners.com
- Vulners: NVD record for CVE-2026-70012 vulners.com
- OpenCVE: CVE-2026-70012 app.opencve.io
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 2 Nov 2026, 19:12.
Original description (NVD)
Use after free 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.
Affected? We can help.
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