CVE-2026-50652: Azure Active Directory Denial of Service Vulnerability

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.7% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-07-14 · updated 2026-10-28
Weakness: CWE-502

Description

Deserialization of untrusted data in Azure Active Directory allows an unauthorized attacker to deny service over a network.

Affected products

Microsoft .NET Framework: 3.5, 4.8.1, 4.6.2, 4.7, 4.7.1, 4.7.2 (+1)
Microsoft Azure Active Directory: all versions
Microsoft Azure Active Directory: from 2021 before 5.7.1 — fixed in 5.7.1
Microsoft .NET Framework 3.5: from 3.5.0 before 2.0.50727.9182 & 3.0.30729.9168 — fixed in 2.0.50727.9182 & 3.0.30729.9168
Microsoft .NET Framework 3.5 AND 4.7.2: from 4.7.0 before 2.0.50727.9069 & 3.0.30729.9067 & 4.7.4143.0 — fixed in 2.0.50727.9069 & 3.0.30729.9067 & 4.7.4143.0
Microsoft .NET Framework 3.5 AND 4.8: from 4.8.0 before 2.0.50727.9069 & 3.0.30729.9067 & 4.8.4803.0 — fixed in 2.0.50727.9069 & 3.0.30729.9067 & 4.8.4803.0
Microsoft .NET Framework 3.5 AND 4.8.1: from 4.8.1 before 2.0.50727.9182 & 3.0.30729.9168 & 4.8.9339.0 — fixed in 2.0.50727.9182 & 3.0.30729.9168 & 4.8.9339.0
Microsoft .NET Framework 4.6.2/4.7/4.7.1/4.7.2: from 4.7.0 before 4.7.4143.0 — fixed in 4.7.4143.0
Microsoft .NET Framework 4.8: from 4.8.0 before 4.8.4803.0 — fixed in 4.8.4803.0
Microsoft .NET Framework 4.8.1: from 4.8.0.0 before 4.8.9340.0 — fixed in 4.8.9340.0

How to fix

Upgrade to a fixed version: Microsoft Azure Active Directory 5.7.1; Microsoft .NET Framework 3.5 2.0.50727.9182 & 3.0.30729.9168; Microsoft .NET Framework 3.5 AND 4.7.2 2.0.50727.9069 & 3.0.30729.9067 & 4.7.4143.0; Microsoft .NET Framework 3.5 AND 4.8 2.0.50727.9069 & 3.0.30729.9067 & 4.8.4803.0; Microsoft .NET Framework 3.5 AND 4.8.1 2.0.50727.9182 & 3.0.30729.9168 & 4.8.9339.0; Microsoft .NET Framework 4.6.2/4.7/4.7.1/4.7.2 4.7.4143.0; Microsoft .NET Framework 4.8 4.8.4803.0; Microsoft .NET Framework 4.8.1 4.8.9340.0. Check the vendor advisory for mitigations.

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-50652

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