What’s Vulnerable › Vulnerabilities

CVE-2023-21722: .NET Framework Denial of Service Vulnerability

• Severity: medium (CVSS 5.0 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.9% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2023-02-14 · updated 2026-08-19
• Weakness: CWE-59

Description

.NET Framework Denial of Service Vulnerability

Affected products

• Microsoft .NET Framework: 3.5, 4.7.2, 4.8, 4.8.1, 3.5.1, 3.0-sp2 (+4)
• Microsoft .NET Framework 2.0 Service Pack 2: from 2.0.0 before 2.0.50727.8966 — fixed in 2.0.50727.8966
• Microsoft .NET Framework 3.0 Service Pack 2: from 3.0.0 before 2.0.50727.8966 — fixed in 2.0.50727.8966
• Microsoft .NET Framework 3.5: from 3.5.0 before 3.5.50727.8966 — fixed in 3.5.50727.8966
• Microsoft .NET Framework 3.5.1: from 3.5.0 before 3.5.50727.8966 — fixed in 3.5.50727.8966
• Microsoft .NET Framework 3.5 and 4.6.2: from 4.7.0 before 10.0.10240.19747 — fixed in 10.0.10240.19747
• Microsoft .NET Framework 3.5 AND 4.7.2: from 4.7.0 before 10.0.04038.03 — fixed in 10.0.04038.03
• Microsoft .NET Framework 3.5 AND 4.8: from 4.8.0 before 10.0.04614.06 — fixed in 10.0.04614.06
• Microsoft .NET Framework 3.5 AND 4.8.1: from 4.8.1 before 10.0.09139.02 — fixed in 10.0.09139.02
• Microsoft .NET Framework 4.6.2: from 4.7.0 before 4.7.04038.06 — fixed in 4.7.04038.06
• Microsoft .NET Framework 4.6.2/4.7/4.7.1/4.7.2: from 4.7.0 before 4.7.04614.08 — fixed in 4.7.04614.08
• Microsoft .NET Framework 4.8: from 4.8.0 before 4.8.4614.08 — fixed in 4.8.4614.08

How to fix

Upgrade to a fixed version: Microsoft .NET Framework 2.0 Service Pack 2 2.0.50727.8966; Microsoft .NET Framework 3.0 Service Pack 2 2.0.50727.8966; Microsoft .NET Framework 3.5 3.5.50727.8966; Microsoft .NET Framework 3.5.1 3.5.50727.8966; Microsoft .NET Framework 3.5 and 4.6.2 10.0.10240.19747; Microsoft .NET Framework 3.5 AND 4.7.2 10.0.04038.03; Microsoft .NET Framework 3.5 AND 4.8 10.0.04614.06; Microsoft .NET Framework 3.5 AND 4.8.1 10.0.09139.02; Microsoft .NET Framework 4.6.2 4.7.04038.06; Microsoft .NET Framework 4.6.2/4.7/4.7.1/4.7.2 4.7.04614.08; Microsoft .NET Framework 4.8 4.8.4614.08. Check the vendor advisory for mitigations.

References

• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21722
• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21722

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