CVE-2026-42909
HIGHCVSS 7.5/10EPSS 0.40%
Last modified
CVE-2026-42909 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. Concurrent execution using shared resource with improper synchronization ('race condition') in Remote Desktop Client allows an unauthorized attacker to execute code over a network.. EPSS estimates a 0.40% chance of exploitation in the next 30 days.
Description
Concurrent execution using shared resource with improper synchronization ('race condition') in Remote Desktop Client allows an unauthorized attacker to execute code over a network.
Metrics
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Microsoft | Remote Desktop Client | < 1.2.7214 |
| Microsoft | Windows App | < 2.0.1193.0 |
| Microsoft | Windows 10 1607 | < 10.0.14393.9234 |
| Microsoft | Windows 10 1809 | < 10.0.17763.8880 |
| Microsoft | Windows 10 21h2 | < 10.0.19044.7417 |
| Microsoft | Windows 10 22h2 | < 10.0.19045.7417 |
| Microsoft | Windows 11 23h2 | < 10.0.22631.7219 |
| Microsoft | Windows 11 24h2 | < 10.0.26100.8655 |
| Microsoft | Windows 11 25h2 | < 10.0.26200.8655 |
| Microsoft | Windows 11 26h1 | < 10.0.28000.2269 |
| Microsoft | Windows Server 2012 | All versions |
| Microsoft | Windows Server 2012 | r2 |
| Microsoft | Windows Server 2016 | < 10.0.14393.9234 |
| Microsoft | Windows Server 2019 | < 10.0.17763.8880 |
| Microsoft | Windows Server 2022 | < 10.0.20348.5256 |
| Microsoft | Windows Server 2025 | < 10.0.26100.32995 |
References
Timeline
- Published
- Last Modified
- Status
- Modified
Frequently Asked Questions
What is 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.
How severe is CVE-2026-42909?
CVE-2026-42909 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 0.40% probability of exploitation in the next 30 days.
How do I fix CVE-2026-42909?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.
How Strix Helps
- How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
- Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
- PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
- AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.
Related CVEs from 2026
- CVE-2026-42903Null pointer dereference in Windows Kerberos allows an autho…6.5
- CVE-2026-42904Heap-based buffer overflow in Windows TCP/IP allows an unaut…9.6
- CVE-2026-42905Use after free in Windows DWM Core Library allows an authori…7.8
- CVE-2026-42906Exposure of sensitive information to an unauthorized actor i…5.5
- CVE-2026-42907Exposure of sensitive information to an unauthorized actor i…6.5
- CVE-2026-42908Out-of-bounds read in Windows RDP allows an unauthorized att…7.5
- CVE-2026-42910Out-of-bounds write in Windows Hotpatch Monitoring Service a…7.8
- CVE-2026-42911Use after free in Windows Ancillary Function Driver for WinS…7
- CVE-2026-42912Concurrent execution using shared resource with improper syn…7
- CVE-2026-42913Concurrent execution using shared resource with improper syn…7.5
- CVE-2026-42914Out-of-bounds read in Windows Kerberos allows an authorized …5.3
- CVE-2026-42915Incorrect calculation of buffer size in Windows VMSwitch all…5.5
Are you affected by CVE-2026-42909?
Run a free Strix scan to check your systems for this vulnerability.
Scan your code nowSource: NVD / NIST