Use of a broken or risky cryptographic algorithm in Microsoft Windows and Windows Server - CVE-2026-59116

Vulnerability identifier: #VU154382

CSH Severity: Medium

CVSS v4: 7 [CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-59116

CWE-ID: CWE-327

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to bypass a security feature.

The vulnerability exists due to use of a broken or risky cryptographic algorithm in Windows Remote Desktop when using cryptography for network connections. A remote attacker can create a SHA1 hash collision to bypass a security feature.

Successful exploitation requires user interaction.

Microsoft Windows
Windows Server

Install security update from vendor's website.

Microsoft Windows - addressed in versions 10 21H2 10.0.19044.7548, 10 22H2 10.0.19045.7548, 10 1607 10.0.14393.9339, 10 1809 10.0.17763.9020, 11 23H2 10.0.22631.7376, 11 24H2 10.0.26100.8875, 11 25H2 10.0.26200.8875, 11 26H1 10.0.28000.2525
Windows Server - addressed in versions 2012 R2 6.3.9600.23291, 2012 6.2.9200.26226, 2016 10.0.14393.9339, 2019 10.0.17763.9020, 2022 10.0.20348.5386, 2025 10.0.26100.33158

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2026-59116

• Use of a broken or risky cryptographic algorithm in Microsoft Windows