What is CVE-2026-23666?

CVE-2026-23666 is a security advisory published by Microsoft Security Response Center (MSRC) with Critical severity. .NET Framework Denial of Service Vulnerability

Which CVE IDs does CVE-2026-23666 cover?

CVE-2026-23666 covers the following CVE IDs: CVE-2026-23666. Each CVE has its own detail page on EchelonGraph Pulse with the synthesized EG score.

What is the CVSS v3 score of CVE-2026-23666?

CVE-2026-23666 has a CVSS v3 base score of 7.5, published by Microsoft Security Response Center (MSRC).

Which products are affected by CVE-2026-23666?

CVE-2026-23666 affects 49 products, including: Microsoft .NET Framework 3.5 AND 4.7.2 on Windows 10 Version 1809 for 32-bit Systems; Microsoft .NET Framework 3.5 AND 4.7.2 on Windows 10 Version 1809 for ARM64-based Systems; Microsoft .NET Framework 3.5 AND 4.7.2 on Windows 10 Version 1809 for x64-based Systems; Microsoft .NET Framework 3.5 AND 4.8 on Windows 10 Version 1809 for 32-bit Systems; Microsoft .NET Framework 3.5 AND 4.8 on Windows 10 Version 1809 for ARM64-based Systems; and others — see the full list on the advisory page.

CVE-2026-23666: .NET Framework Denial of Ser…

🔗 CVE IDs covered (1)

CVE-2026-23666 →

📋 Description

Improper input validation in .NET Framework allows an unauthorized attacker to deny service over a network.

🎯 Affected products49

Microsoft .NET Framework 3.5 AND 4.7.2 on Windows 10 Version 1809 for 32-bit Systems
Microsoft .NET Framework 3.5 AND 4.7.2 on Windows 10 Version 1809 for ARM64-based Systems
Microsoft .NET Framework 3.5 AND 4.7.2 on Windows 10 Version 1809 for x64-based Systems
Microsoft .NET Framework 3.5 AND 4.8 on Windows 10 Version 1809 for 32-bit Systems
Microsoft .NET Framework 3.5 AND 4.8 on Windows 10 Version 1809 for ARM64-based Systems
Microsoft .NET Framework 3.5 AND 4.8 on Windows 10 Version 1809 for x64-based Systems
Microsoft .NET Framework 3.5 AND 4.8 on Windows 10 Version 21H2 for 32-bit Systems
Microsoft .NET Framework 3.5 AND 4.8 on Windows 10 Version 21H2 for ARM64-based Systems
Microsoft .NET Framework 3.5 AND 4.8 on Windows 10 Version 21H2 for x64-based Systems
Microsoft .NET Framework 3.5 AND 4.8 on Windows 10 Version 22H2 for 32-bit Systems
Microsoft .NET Framework 3.5 AND 4.8 on Windows 10 Version 22H2 for ARM64-based Systems
Microsoft .NET Framework 3.5 AND 4.8 on Windows 10 Version 22H2 for x64-based Systems
Microsoft .NET Framework 3.5 AND 4.8 on Windows Server 2022
Microsoft .NET Framework 3.5 AND 4.8 on Windows Server 2022 (Server Core installation)
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 10 Version 21H2 for 32-bit Systems
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 10 Version 21H2 for ARM64-based Systems
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 10 Version 21H2 for x64-based Systems
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 10 Version 22H2 for 32-bit Systems
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 10 Version 22H2 for ARM64-based Systems
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 10 Version 22H2 for x64-based Systems
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 11 Version 22H2 for ARM64-based Systems
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 11 Version 22H2 for x64-based Systems
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 11 Version 23H2 for ARM64-based Systems
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 11 Version 23H2 for x64-based Systems
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 11 Version 24H2 for ARM64-based Systems
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 11 Version 24H2 for x64-based Systems
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 11 Version 25H2 for ARM64-based Systems
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 11 Version 25H2 for x64-based Systems
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 11 Version 26H1 for ARM64-based Systems
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 11 version 26H1 for x64-based Systems
+19 more not shown

✅ Remediation

KB5082411 (Security Update) — fixed build 4.8.4801.0 KB5082403 (Security Update) — fixed build 4.8.4801.0 KB5082404 (Security Update) — fixed build 4.8.4801.0 KB5082414 (Security Update) — fixed build 2.0.50727.9068 & 3.0.30729.9065 & 4.8.4801.0 KB5082427 (Security Update) — fixed build 2.0.50727.9181 & 3.0.30729.9165 & 4.8.4801.0 KB5082426 (Security Update) — fixed build 2.0.50727.9181 & 3.0.30729.9165 & 4.8.4801.0 KB5082413 (Security Update) — fixed build 2.0.50727.9068 & 3.0.30729.9065 & 4.7.4141.0 KB5082400 (Security Update) — fixed build 4.8.4801.0 KB5082402 (Security Update) — fixed build 4.7.4141.0 KB5082425 (Security Update) — fixed build 2.0.50727.9181 & 3.0.30729.9165 & 4.8.9332.0 KB5082419 (Security Update) — fixed build 2.0.50727.9181 & 3.0.30729.9165 & 4.8.9332.0 KB5082424 (Security Update) — fixed build 2.0.50727.9181 & 3.0.30729.9165 & 4.8.9332.0 KB5082417 (Security Update) — fixed build 2.0.50727.9181 & 3.0.30729.9165 & 4.8.9332.0 KB5082418 (Security Update) — fixed build 2.0.50727.9181 & 3.0.30729.9165 & 4.8.9332.0 KB5082420 (Security Update) — fixed build 2.0.50727.9181 & 3.0.30729.9165 & 4.8.9332.0 KB5082398 (Security Update) — fixed build 2.0.50727.8982 & 3.0.30729.8976 KB5082406 (Security Update) — fixed build 2.0.50727.8982 & 3.0.30729.8976 KB5082421 (Security Update) — fixed build 2.0.50727.9181 & 3.0.30729.9165 & 4.8.9332.0

🔗 CVE IDs covered (1)

📋 Description

🎯 Affected products49

✅ Remediation

🔗 References (37)