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
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.005 (37.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 38th percentile — 37.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.005 · change: +0.001
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
- Remote Desktop Client Remote Code Execution Vulnerability (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.