CVE-2026-105016: Microsoft QUIC Remote Code Execution Vulnerability

Severity: critical (CVSS 9.8 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: 2026-10-13 · updated 2026-10-31
Weakness: CWE-122

Description

Heap-based buffer overflow in Microsoft QUIC allows an unauthorized attacker to execute code over a network.

Affected products

Microsoft .NET 10.0 runtime: from 10.0.0 before 10.0.14 — fixed in 10.0.14
Microsoft .NET 11.0 runtime: from 11.0.0 before 11.0.0-rc.2.26504.105 — fixed in 11.0.0-rc.2.26504.105
Microsoft .NET 8.0 runtime: from 8.0.0 before 8.0.32 — fixed in 8.0.32
Microsoft .NET 9.0 runtime: from 9.0.0 before 9.0.21 — fixed in 9.0.21
Microsoft Visual Studio 2026 version 18.10: from 18.10.0 before 18.10.4 — fixed in 18.10.4
Microsoft Visual Studio 2022 version 17.14: from 17.14.0 before 17.14.42 — fixed in 17.14.42
Microsoft Windows 11: from 10.0.22631.0 before 10.0.22631.7652 — fixed in 10.0.22631.7652
Microsoft Windows 11: from 10.0.26100.0 before 10.0.26100.9711 — fixed in 10.0.26100.9711
Microsoft Windows 11 25H2: from 10.0.26200.0 before 10.0.26200.9711 — fixed in 10.0.26200.9711
Microsoft Windows 11 version 26H1: from 10.0.28000.0 before 10.0.28000.3231 — fixed in 10.0.28000.3231
Microsoft Windows 11 26H2: from 10.0.26300.0 before 10.0.26300.9711 — fixed in 10.0.26300.9711
Microsoft Windows Server 2022: from 10.0.20348.0 before 10.0.20348.5761 — fixed in 10.0.20348.5761
Microsoft Windows Server 2025: from 10.0.26100.0 before 10.0.26100.33650 — fixed in 10.0.26100.33650

How to fix

Upgrade to a fixed version: Microsoft .NET 10.0 runtime 10.0.14; Microsoft .NET 11.0 runtime 11.0.0-rc.2.26504.105; Microsoft .NET 8.0 runtime 8.0.32; Microsoft .NET 9.0 runtime 9.0.21; Microsoft Visual Studio 2026 version 18.10 18.10.4; Microsoft Visual Studio 2022 version 17.14 17.14.42; Microsoft Windows 11 10.0.22631.7652; Microsoft Windows 11 10.0.26100.9711; Microsoft Windows 11 25H2 10.0.26200.9711; Microsoft Windows 11 version 26H1 10.0.28000.3231; Microsoft Windows 11 26H2 10.0.26300.9711; Microsoft Windows Server 2022 10.0.20348.5761. Check the vendor advisory for mitigations.

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-105016

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