CVE-2026-108398

.NET Framework Security Feature Bypass Vulnerability

CVE-2026-108398 is fixed in 24 products on 1 platform, first by KB5126868, released October 13, 2026. It is not reported as exploited. Patch Radar priority: High.

HighPublicly disclosed
CVSS
8.8
Important
Exploitation
None reported
Exploitation Less Likely
CISA KEV
Not listed
Not in the Known Exploited Vulnerabilities catalog
EPSS
0.0078
56th percentile

<p>Untrusted search path in .NET Framework allows an authorized attacker to bypass a security feature locally.</p>

Where it's fixed

ProductFixed inFixReleased
Microsoft
Microsoft .NET Framework 3.5 AND 4.6.2/4.7/4.7.1/4.7.2 on Windows 10 version 1607 14393.9612 KB5126868 Oct 13, 2026
Microsoft .NET Framework 3.5 AND 4.6.2/4.7/4.7.1/4.7.2 on Windows Server 2016 14393.9612 KB5126868 Oct 13, 2026
Microsoft .NET Framework 3.5 AND 4.6.2/4.7/4.7.1/4.7.2 on Windows Server 2019 KB5127666 Oct 13, 2026
Microsoft .NET Framework 3.5 AND 4.7.2 on Windows 10 version 1809 KB5127666 Oct 13, 2026
Microsoft .NET Framework 3.5 AND 4.8 on Windows 10 version 1809 KB5127685 Oct 13, 2026
Microsoft .NET Framework 3.5 AND 4.8 on Windows 10 version 21H2 KB5127683 Oct 13, 2026
Microsoft .NET Framework 3.5 AND 4.8 on Windows 10 version 22H2 KB5127683 Oct 13, 2026
Microsoft .NET Framework 3.5 AND 4.8 on Windows Server 2019 KB5127685 Oct 13, 2026
Microsoft .NET Framework 3.5 AND 4.8 on Windows Server 2022 KB5127687 Oct 13, 2026
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 10 version 21H2 KB5127689 Oct 13, 2026
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 10 version 22H2 KB5127689 Oct 13, 2026
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 11 version 23H2 KB5127692 Oct 13, 2026
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 11 version 24H2 KB5127690 Oct 13, 2026
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 11 version 25H2 KB5127690 Oct 13, 2026
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 11 version 26H2 KB5127694 Oct 13, 2026
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows Server 2022 KB5127693 Oct 13, 2026
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows Server 2025 KB5127690 Oct 13, 2026
Microsoft .NET Framework 4.6.2/4.7/4.7.1/4.7.2 on Windows Server 2012 KB5127667 Oct 13, 2026
Microsoft .NET Framework 4.6.2/4.7/4.7.1/4.7.2 on Windows Server 2012 R2 KB5127668 Oct 13, 2026
Microsoft .NET Framework 4.8 on Windows 10 version 1607 KB5127684 Oct 13, 2026
Microsoft .NET Framework 4.8 on Windows Server 2012 KB5127686 Oct 13, 2026
Microsoft .NET Framework 4.8 on Windows Server 2012 R2 KB5127688 Oct 13, 2026
Microsoft .NET Framework 4.8 on Windows Server 2016 KB5127684 Oct 13, 2026
Microsoft .NET Framework 4.8.1 on Windows 11 version 26H1 KB5127691 Oct 13, 2026