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CVE-2026-65810

High CVSS 7.8

Published 2026-08-11 ยท last changed 2026-08-14

The fix

Microsoft fixes this in updatesKB5120418, KB5120698, KB5120709, KB5120713, KB5120710, KB5120708, KB5120714, KB5120703, KB5120701, KB5120705, KB5120747, KB5120716, KB5120695, KB5120699, KB5120700, KB5120711, KB5120702, KB5120704, KB5120706. The fixed build differs per Windows version, so the row that matters is the one matching the machine you are looking at.

Windows version Fixed in build Update Released
Microsoft .NET Framework 3.5 AND 4.6.2/4.7/4.7.1/4.7.2 on Windows 10 Version 1607 for 32-bit Systems 2.0.50727.8984 & 3.0.30729.8980 & 4.7.4144.0 KB5120418 2026-09-20
Microsoft .NET Framework 3.5 AND 4.6.2/4.7/4.7.1/4.7.2 on Windows 10 Version 1607 for x64-based Systems 2.0.50727.8984 & 3.0.30729.8980 & 4.7.4144.0 KB5120418 2026-09-20
Microsoft .NET Framework 3.5 AND 4.6.2/4.7/4.7.1/4.7.2 on Windows Server 2016 2.0.50727.8984 & 3.0.30729.8980 & 4.7.4144.0 KB5120418 2026-09-20
Microsoft .NET Framework 3.5 AND 4.6.2/4.7/4.7.1/4.7.2 on Windows Server 2016 (Server Core installation) 2.0.50727.8984 & 3.0.30729.8980 & 4.7.4144.0 KB5120418 2026-09-20
Microsoft .NET Framework 3.5 AND 4.7.2 on Windows 10 Version 1809 for 32-bit Systems 2.0.50727.9070 & 3.0.30729.9068 & 4.7.4144.0 KB5120698 2026-09-20
Microsoft .NET Framework 3.5 AND 4.7.2 on Windows 10 Version 1809 for ARM64-based Systems 2.0.50727.9070 & 3.0.30729.9068 & 4.7.4144.0 KB5120698 2026-09-20
Microsoft .NET Framework 3.5 AND 4.7.2 on Windows 10 Version 1809 for x64-based Systems 2.0.50727.9070 & 3.0.30729.9068 & 4.7.4144.0 KB5120698 2026-09-20
Microsoft .NET Framework 3.5 AND 4.7.2 on Windows Server 2019 2.0.50727.9070 & 3.0.30729.9068 & 4.7.4144.0 KB5120698 2026-09-20
Microsoft .NET Framework 3.5 AND 4.7.2 on Windows Server 2019 (Server Core installation) 2.0.50727.9070 & 3.0.30729.9068 & 4.7.4144.0 KB5120698 2026-09-20
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 10 Version 21H2 for 32-bit Systems 2.0.50727.9183 & 3.0.30729.9169 & 4.8.9343.0 KB5120709 2026-09-20
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 10 Version 21H2 for ARM64-based Systems 2.0.50727.9183 & 3.0.30729.9169 & 4.8.9343.0 KB5120709 2026-09-20
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 10 Version 21H2 for x64-based Systems 2.0.50727.9183 & 3.0.30729.9169 & 4.8.9343.0 KB5120709 2026-09-20
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 10 Version 22H2 for 32-bit Systems 2.0.50727.9183 & 3.0.30729.9169 & 4.8.9343.0 KB5120709 2026-09-20
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 10 Version 22H2 for ARM64-based Systems 2.0.50727.9183 & 3.0.30729.9169 & 4.8.9343.0 KB5120709 2026-09-20
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 10 Version 22H2 for x64-based Systems 2.0.50727.9183 & 3.0.30729.9169 & 4.8.9343.0 KB5120709 2026-09-20
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 11 Version 23H2 for ARM64-based Systems 2.0.50727.9183 & 3.0.30729.9169 & 4.8.9343.0 KB5120713 2026-09-20
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 11 Version 23H2 for x64-based Systems 2.0.50727.9183 & 3.0.30729.9169 & 4.8.9343.0 KB5120713 2026-09-20
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 11 Version 24H2 for ARM64-based Systems 2.0.50727.9183 & 3.0.30729.9169 & 4.8.9343.0 KB5120710 2026-09-20
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 11 Version 24H2 for x64-based Systems 2.0.50727.9183 & 3.0.30729.9169 & 4.8.9343.0 KB5120710 2026-09-20
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 11 Version 25H2 for ARM64-based Systems 2.0.50727.9183 & 3.0.30729.9169 & 4.8.9344.0 KB5120708 2026-09-20
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows 11 Version 25H2 for x64-based Systems 2.0.50727.9183 & 3.0.30729.9169 & 4.8.9344.0 KB5120708 2026-09-20
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows Server 2022 2.0.50727.9183 & 3.0.30729.9169 & 4.8.9343.0 KB5120714 2026-09-20
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows Server 2022 (Server Core installation) 2.0.50727.9183 & 3.0.30729.9169 & 4.8.9343.0 KB5120714 2026-09-20
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows Server 2025 2.0.50727.9183 & 3.0.30729.9169 & 4.8.9344.0 KB5120708 2026-09-20
Microsoft .NET Framework 3.5 AND 4.8.1 on Windows Server 2025 (Server Core installation) 2.0.50727.9183 & 3.0.30729.9169 & 4.8.9344.0 KB5120708 2026-09-20
Microsoft .NET Framework 3.5 AND 4.8 on Windows 10 Version 1809 for 32-bit Systems 2.0.50727.9070 & 3.0.30729.9068 & 4.8.4805.0 KB5120703 2026-09-20
Microsoft .NET Framework 3.5 AND 4.8 on Windows 10 Version 1809 for ARM64-based Systems 2.0.50727.9070 & 3.0.30729.9068 & 4.8.4805.0 KB5120703 2026-09-20
Microsoft .NET Framework 3.5 AND 4.8 on Windows 10 Version 1809 for x64-based Systems 2.0.50727.9070 & 3.0.30729.9068 & 4.8.4805.0 KB5120703 2026-09-20
Microsoft .NET Framework 3.5 AND 4.8 on Windows 10 Version 21H2 for 32-bit Systems 2.0.50727.9183 & 3.0.30729.9169 & 4.8.4805.0 KB5120701 2026-09-20
Microsoft .NET Framework 3.5 AND 4.8 on Windows 10 Version 21H2 for ARM64-based Systems 2.0.50727.9183 & 3.0.30729.9169 & 4.8.4805.0 KB5120701 2026-09-20
Microsoft .NET Framework 3.5 AND 4.8 on Windows 10 Version 21H2 for x64-based Systems 2.0.50727.9183 & 3.0.30729.9169 & 4.8.4805.0 KB5120701 2026-09-20
Microsoft .NET Framework 3.5 AND 4.8 on Windows 10 Version 22H2 for 32-bit Systems 2.0.50727.9183 & 3.0.30729.9169 & 4.8.4805.0 KB5120701 2026-09-20
Microsoft .NET Framework 3.5 AND 4.8 on Windows 10 Version 22H2 for ARM64-based Systems 2.0.50727.9183 & 3.0.30729.9169 & 4.8.4805.0 KB5120701 2026-09-20
Microsoft .NET Framework 3.5 AND 4.8 on Windows 10 Version 22H2 for x64-based Systems 2.0.50727.9183 & 3.0.30729.9169 & 4.8.4805.0 KB5120701 2026-09-20
Microsoft .NET Framework 3.5 AND 4.8 on Windows Server 2019 2.0.50727.9070 & 3.0.30729.9068 & 4.8.4805.0 KB5120703 2026-09-20
Microsoft .NET Framework 3.5 AND 4.8 on Windows Server 2019 (Server Core installation) 2.0.50727.9070 & 3.0.30729.9068 & 4.8.4805.0 KB5120703 2026-09-20
Microsoft .NET Framework 3.5 AND 4.8 on Windows Server 2022 2.0.50727.9183 & 3.0.30729.9169 & 4.8.4805.0 KB5120705 2026-09-20
Microsoft .NET Framework 3.5 AND 4.8 on Windows Server 2022 (Server Core installation) 2.0.50727.9183 & 3.0.30729.9169 & 4.8.4805.0 KB5120705 2026-09-20
Microsoft .NET Framework 3.5 on Windows 11 Version 26H1 for ARM64-based Systems 2.0.50727.9183 & 3.0.30729.9169 KB5120747 2026-09-20
Microsoft .NET Framework 3.5 on Windows 11 version 26H1 for x64-based Systems 2.0.50727.9183 & 3.0.30729.9169 KB5120747 2026-09-20
Microsoft .NET Framework 3.5 on Windows Server 2012 2.0.50727.8984 & 3.0.30729.8980 KB5120716 2026-09-20
Microsoft .NET Framework 3.5 on Windows Server 2012 R2 2.0.50727.8984 & 3.0.30729.8980 KB5120695 2026-09-20
Microsoft .NET Framework 3.5 on Windows Server 2012 R2 (Server Core installation) 2.0.50727.8984 & 3.0.30729.8980 KB5120695 2026-09-20
Microsoft .NET Framework 3.5 on Windows Server 2012 (Server Core installation) 2.0.50727.8984 & 3.0.30729.8980 KB5120716 2026-09-20
Microsoft .NET Framework 4.6.2/4.7/4.7.1/4.7.2 on Windows Server 2012 4.7.4144.0 KB5120699 2026-09-20
Microsoft .NET Framework 4.6.2/4.7/4.7.1/4.7.2 on Windows Server 2012 R2 4.7.4144.0 KB5120700 2026-09-20
Microsoft .NET Framework 4.6.2/4.7/4.7.1/4.7.2 on Windows Server 2012 R2 (Server Core installation) 4.7.4144.0 KB5120700 2026-09-20
Microsoft .NET Framework 4.6.2/4.7/4.7.1/4.7.2 on Windows Server 2012 (Server Core installation) 4.7.4144.0 KB5120699 2026-09-20
Microsoft .NET Framework 4.8.1 on Windows 11 Version 26H1 for ARM64-based Systems 4.8.9344.0 KB5120711 2026-09-20
Microsoft .NET Framework 4.8.1 on Windows 11 version 26H1 for x64-based Systems 4.8.9344.0 KB5120711 2026-09-20
Microsoft .NET Framework 4.8 on Windows 10 Version 1607 for 32-bit Systems 4.8.4805.0 KB5120702 2026-09-20
Microsoft .NET Framework 4.8 on Windows 10 Version 1607 for x64-based Systems 4.8.4805.0 KB5120702 2026-09-20
Microsoft .NET Framework 4.8 on Windows Server 2012 4.8.4805.0 KB5120704 2026-09-20
Microsoft .NET Framework 4.8 on Windows Server 2012 R2 4.8.4805.0 KB5120706 2026-09-20
Microsoft .NET Framework 4.8 on Windows Server 2012 R2 (Server Core installation) 4.8.4805.0 KB5120706 2026-09-20
Microsoft .NET Framework 4.8 on Windows Server 2012 (Server Core installation) 4.8.4805.0 KB5120704 2026-09-20
Microsoft .NET Framework 4.8 on Windows Server 2016 4.8.4805.0 KB5120702 2026-09-20
Microsoft .NET Framework 4.8 on Windows Server 2016 (Server Core installation) 4.8.4805.0 KB5120702 2026-09-20

Having the KB is not the same as knowing whether a machine has it. Windows updates supersede each other, so the update you installed often covers a fix that shipped in an earlier one. Paste your build into the patch checker and it walks that chain for you.

What it is

Relative path traversal in .NET Framework allows an unauthorized attacker to elevate privileges locally.

Sources

CVSS vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H