Windows Remote Desktop Client: Remote code execution via use-after-free
Summary
A use-after-free flaw (CWE-416) in the Remote Desktop Client of Microsoft Windows allows an unauthenticated remote attacker to execute code. Per the CVSS vector, the attack is rated high complexity and requires a user action, such as connecting to a malicious RDP host, but no privileges. The CVSS 3.1 base score is 7.5 (High).
Affected
- Windows 10 Version 1607: 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 (incl. Server Core): before 6.2.9200.26434
- Windows Server 2012 R2 (incl. Server Core): before 6.3.9600.23470
- Windows Server 2016: before 10.0.14393.9612
- Windows Server 2019, 2022 and 2025: not listed in the CNA record, unknown
Fixed in
- Fixed builds are the versions listed above, per the CNA record.
- Reported KB numbers (KB5126651 for Windows 10 1809 and Server 2019, KB5126646 for Windows Server 2025) are unverified. Confirm the correct update on the MSRC advisory before deployment.
Workaround
- Unknown from the vendor advisory.
- Until patched, disable Remote Desktop connections or restrict them to trusted hosts (secondary source guidance).
Exploitation
- Not listed in CISA KEV.
- CISA SSVC: exploitation none, automatable no, technical impact total.
- No public proof of concept or observed exploitation found as of the research date. This is not a confirmed absence.
Our recommendation
- Patch Windows clients and admin workstations first using the update listed in the MSRC advisory.
- Check whether Windows 10 1607 machines still receive security updates. If not, plan an upgrade or isolate them.
- Restrict outbound RDP connections to known, trusted hosts.
- Check which systems have Remote Desktop Client in use and monitor for unusual RDP connections.
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 less likely
- Product family
- Windows, Windows ESU (Extended Security Updates)
- Updates (KB)
- KB5126651, KB5126655, KB5126657, KB5126646, KB5127648, KB5126653
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Microsoft Security Update Guide (MSRC) msrc.microsoft.com
- VulnDB / Vulners NVD record vulners.com
- Vulners CVE List record vulners.com
- OpenCVE CVE-2026-69997 app.opencve.io
- CVEfeed CVE-2026-69997 cvefeed.io
- VulDB entry 418322 vuldb.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 2 Nov 2026, 19:17.
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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