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Vulnerability record · CVE-2025-55340 · published 14 October 2025

CVE-2025-55340: Microsoft windows 10 21h2 improper authentication vulnerability

Microsoft · Windows 10 21h2

Improper authentication in Windows Remote Desktop Protocol allows an authorized attacker to bypass a security feature locally.

7.0 CVSS 3.1 High EPSS 0.31% · top 78.6% CWE-287 · Improper authentication
7.0CVSS 3.1 base score
0.31%EPSS exploitation probability, 30 days
NoNot in CISA KEV
9Affected product versions listed by NVD
1References
17 Jun 2026Last modified by NVD

Description

Improper authentication in Windows Remote Desktop Protocol allows an authorized attacker to bypass a security feature locally.

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

9 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-55340 Vendor Advisory

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Source: NIST National Vulnerability Database (record CVE-2025-55340), CISA KEV, FIRST EPSS (scores of 2026-09-29). This page is refreshed as NVD updates the record.