Deserialization of Untrusted Data in Microsoft .NET Framework - CVE-2026-50652

Vulnerability identifier: #VU138287

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-2026-50652

CWE-ID: CWE-502

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 deserialization of untrusted data in Azure Active Directory when processing untrusted serialized data over the network. A remote attacker can send crafted serialized data to cause a denial of service.

Microsoft .NET Framework

Install security update from vendor's website.

Microsoft .NET Framework - addressed in versions 2.0.50727.8983 & 3.0.30729.8978, 2.0.50727.8983 & 3.0.30729.8978 & 4.7.4143.0, 2.0.50727.9069 & 3.0.30729.9067 & 4.7.4143.0, 2.0.50727.9069 & 3.0.30729.9067 & 4.8.4803.0, 2.0.50727.9182 & 3.0.30729.9168, 2.0.50727.9182 & 3.0.30729.9168 & 4.8.4803.0, 2.0.50727.9182 & 3.0.30729.9168 & 4.8.9339.0, 2.0.50727.9182 & 3.0.30729.9168 & 4.8.9340.0, 4.7.4143.0, 4.8.4803.0

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2026-50652
• https://github.com/AzureAD/azure-activedirectory-identitymodel-extensions-for-dotnet/releases/tag/8.19.2

• Multiple vulnerabilities in Microsoft .NET Framework