What’s Vulnerable › Vulnerabilities

CVE-2023-35298: HTTP.sys Denial of Service Vulnerability

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.8% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2023-07-11 · updated 2026-06-17
• Weakness: CWE-400

Description

HTTP.sys Denial of Service Vulnerability

Affected products

• Microsoft Windows 11 21H2: before 10.0.22000.2176 — fixed in 10.0.22000.2176
• Microsoft Windows 11: before 10.0.22621.1992 — fixed in 10.0.22621.1992
• Microsoft Windows Server 2022: all versions
• Microsoft Windows 11 21H2: from 10.0.0 before 10.0.22000.2176 — fixed in 10.0.22000.2176
• Microsoft Windows 11: from 10.0.22621.0 before 10.0.22621.1992 — fixed in 10.0.22621.1992
• Microsoft Windows Server 2022: from 10.0.20348.0 before 10.0.20348.1850 — fixed in 10.0.20348.1850

How to fix

Upgrade to a fixed version: Microsoft Windows 11 21H2 10.0.22000.2176; Microsoft Windows 11 10.0.22621.1992; Microsoft Windows 11 21H2 10.0.22000.2176; Microsoft Windows 11 10.0.22621.1992; Microsoft Windows Server 2022 10.0.20348.1850. Check the vendor advisory for mitigations.

References

• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-35298
• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-35298

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