Use After Free in Microsoft Remote_desktop_client
CVE-2026-42909
Concurrent execution using shared resource with improper synchronization ('race condition') in Remote Desktop Client allows an unauthorized attacker to execute code over a network.
Vulnerability class: Race Condition
EPSS: 0.004 (32.4th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H.
Affected products
- Microsoft Remote_desktop_client
- Microsoft Remote Desktop Client For Windows — versions 1.2.0.0
- Microsoft Windows_10_1607
- Microsoft Windows_10_1809
- Microsoft Windows_10_21h2
- Microsoft Windows_10_22h2
- Microsoft Windows 10 Version 1607 — versions 10.0.14393.0
- Microsoft Windows 10 Version 1809 — versions 10.0.17763.0
- Microsoft Windows 10 Version 21h2 — versions 10.0.19044.0
- Microsoft Windows 10 Version 22h2 — versions 10.0.19045.0
Weakness classification (CWE)
References
- secure@microsoft.com (vendor-advisory, patch, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-42909?
- CVE-2026-42909 is a high-severity vulnerability in Microsoft Remote_desktop_client, classified under Concurrent Execution using Shared Resource with Improper Synchronization (Race Condition). CVSS score: 7.5/10. Published 2026-06-09.
- How severe is CVE-2026-42909?
- High severity. CVSS v3 base score is 7.5 out of 10.