Inefficient Algorithmic Complexity in Visual Studio and Microsoft .NET Framework - CVE-2026-84008

Vulnerability identifier: #VU155081

CSH Severity: Medium

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

CVE-ID: CVE-2026-84008

CWE-ID: CWE-407

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to inefficient algorithmic complexity in .NET when handling network input. A remote attacker can trigger the affected functionality over a network to cause a denial of service.

Visual Studio
Microsoft .NET Framework

Install security update from vendor's website.

Visual Studio - update to 17.14.42
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

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2026-84008
• https://www.nuget.org/packages/System.Security.Cryptography.Pkcs

• Multiple vulnerabilities in Microsoft Windows