CVE-2026-70161
High CVSS 7.3Published 2026-10-13 ยท last changed 2026-10-13
The fix
Microsoft fixes this in updateKB5130036. 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 |
|---|---|---|---|
| .NET 10.0 installed on Windows | 10.0.402 | KB5130036 | 2026-10-13 |
| .NET 11.0 installed on Windows | 11.0.100-rc.2 | configuration change | 2026-10-13 |
| .NET 9.0 installed on Windows | 9.0.319, 9.0.122 | configuration change | 2026-10-13 |
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
Improper limitation of a pathname to a restricted directory ('path traversal') in .NET allows an authorized attacker to elevate privileges locally.
Sources
CVSS vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H