Auth bypass in Microsoft Windows_10_21h2
CVE-2025-55340
Improper authentication in Windows Remote Desktop Protocol allows an authorized attacker to bypass a security feature locally.
Vulnerability class: Broken Authentication
EPSS: 0.003 (19.7th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.0 (High). Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H.
Affected products
- Microsoft Windows_10_21h2
- Microsoft Windows_10_22h2
- Microsoft Windows 10 Version 21h2 — versions 10.0.19044.0
- Microsoft Windows 10 Version 22h2 — versions 10.0.19045.0
- Microsoft Windows_11_22h2
- Microsoft Windows_11_23h2
- Microsoft Windows_11_24h2
- Microsoft Windows_11_25h2
- Microsoft Windows 11 Version 22h2 — versions 10.0.22621.0
- Microsoft Windows 11 Version 22h3 — versions 10.0.22631.0
Weakness classification (CWE)
References
- secure@microsoft.com (vendor-advisory, patch, Vendor Advisory)
Frequently asked questions
- What is CVE-2025-55340?
- CVE-2025-55340 is a high-severity vulnerability in Microsoft Windows_10_21h2, classified under Improper Authentication. CVSS score: 7.0/10. Published 2025-10-14.
- How severe is CVE-2025-55340?
- High severity. CVSS v3 base score is 7.0 out of 10.