Remote code execution via use-after-free race
Published Jun 9, 2026 · Updated Jun 9, 2026
Race condition in Microsoft Remote Desktop Client allows remote attackers to execute code after a user connects to a malicious RDP server. Concurrent client operations improperly synchronize access to a shared resource, allowing one operation to use memory after another frees it. Exploitation requires user interaction and a network connection to an attacker-controlled or compromised RDP server; successful exploitation runs attacker code in the client context.
Summary
What happened
Race condition in Microsoft Remote Desktop Client allows remote attackers to execute code after a user connects to a malicious RDP server. Concurrent client operations improperly synchronize access to a shared resource, allowing one operation to use memory after another frees it. Exploitation requires user interaction and a network connection to an attacker-controlled or compromised RDP server; successful exploitation runs attacker code in the client context.
The record
- CVE
- CVE-2026-42909
- Published
- Jun 9, 2026
- Updated
- Jun 9, 2026
- Vendor
- Microsoft
- Product
- Windows Server 2019
- Classifications
- CWE-362, CWE-416, T1203
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 9, 2026CVE publishedPublication date reported by the CVE source.
- Jun 9, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=10.0.17763.0 <10.0.17763.8880
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo