Use of a broken or risky cryptographic algorithm in Microsoft products - CVE-2026-97788

Vulnerability identifier: #VU155605

CSH Severity: Medium

CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-97788

CWE-ID: CWE-327

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to disclose sensitive information related to a user's or service's active session.

The vulnerability exists due to use of a weak encryption algorithm or cipher in Active Directory Federation Services (AD FS) when encrypting traffic sent over a network. A remote attacker can decrypt network traffic sent by the vulnerable component to disclose sensitive information related to a user's or service's active session.

Microsoft Windows
Windows Server
Microsoft .NET Framework

Install security update from vendor's website.

Microsoft Windows - addressed in versions 10 21H2 10.0.19044.7807, 10 1607 10.0.14393.9612, 10 1809 10.0.17763.9376, 11 23H2 10.0.22631.7652, 11 24H2 10.0.26100.9711, 11 25H2 10.0.26200.9711, 11 26H1 10.0.28000.3231
Microsoft .NET Framework - addressed in versions 2.0.50727.8987 AND 3.0.30729.8982, 2.0.50727.8987 AND 3.0.30729.8982 AND 4.7.4150.0, 2.0.50727.9073 AND 3.0.30729.9070 AND 4.8.4811.0, 2.0.50727.9188 AND 3.0.30729.9171 AND 4.8.4811.0, 2.0.50727.9188 AND 3.0.30729.9171 AND 4.8.9363.0, 4.7.4150.0, 4.8.4811.0
Windows Server - addressed in versions 2012 R2 6.3.9600.23470, 2012 6.2.9200.26434, 2016 10.0.14393.9612, 2019 10.0.17763.9376, 2022 10.0.20348.5761, 2025 10.0.26100.33650

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2026-97788
• https://support.microsoft.com/help/5126868

• Multiple vulnerabilities in Microsoft Windows