[Security] Host folder shares might be unavailable in Hyper-V-based Linux VMs. After installing the September 2026 security update KB5122880, applications that use HCS-managed virtual machines might experience issues when sharing host folder with Linux VMs using Plan9. Affected virtual machines start normally, but folders shared from the Windows host using Plan9 do not appear or cannot be accessed in the guest environment.
⚠️ Known Issues: Host folder shares unavailable in Hyper-V-based Linux VMs
Symptoms: Applications that use HCS-managed virtual machines might experience issues when sharing host folder with Linux VMs using Plan9. Affected virtual machines start normally, but folders shared from the Windows host using Plan9 do not appear or cannot be accessed in the guest environment.