CVE-2025-55340 Windows Remote Desktop Protocol Security Feature Bypass
An authorized local attacker can bypass security features in Windows Remote Desktop Protocol due to improper authentication.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2025-55340?
CVE-2025-55340 is a high-severity vulnerability in Microsoft Windows 10 21h2, published on 14 Oct 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
Improper authentication in Windows Remote Desktop Protocol allows an authorized attacker to bypass a security feature locally.
Weakness: CWE-287
Which versions are affected by CVE-2025-55340?
It affects 9 products.
Products include Microsoft Windows 10 21h2, Microsoft Windows 10 22h2, Microsoft Windows 11 22h2, Microsoft Windows 11 23h2, Microsoft Windows 11 24h2, Microsoft Windows 11 25h2 and 3 more.
How do I fix CVE-2025-55340?
No fix has been published for CVE-2025-55340 yet. Limit exposure of the affected software until one is available.
Is CVE-2025-55340 being exploited?
There is no known exploitation of CVE-2025-55340 in the wild and no public exploit code.
Other vulnerabilities in Microsoft Windows 10 21h2
- CVE-2025-21333 Microsoft Windows Hyper-V NT Kernel Integration VSP Heap-based Buffer Overflow
- CVE-2025-21334 Microsoft Windows Hyper-V NT Kernel Integration VSP Use-After-Free
- CVE-2025-21335 Microsoft Windows Hyper-V NT Kernel Integration VSP Use-After-Free
- CVE-2026-42904 Windows TCP/IP Elevation of Privilege Vulnerability
- CVE-2026-105733 Windows Hyper-V Remote Code Execution Vulnerability
Sources
Also known as GHSA-mx76-c5mq-wfcc.