Microsoft documents in KB5127936 (preview dated October 28, 2026, builds 26300.9818 / 26200.9818 for Windows 11 26H2 / 25H2) a [Windows Subsystem for Linux (WSL)] item under normal rollout:
- The update fixes an issue where nested virtualization might not be available in Windows Subsystem for Linux version 2 (WSL2) on devices with AMD processors.
Attribute only that KB bullet. Do not invent CPU model lists, BIOS toggle recipes, or a repro protocol beyond Microsoft’s wording.
The same KB notes that Windows 11 24H2 no longer receives non-security preview updates starting with the October 2026 release — this optional preview path therefore concerns 25H2 / 26H2. Typical optional-preview path: Settings > Windows Update > Advanced options > Optional updates. On a managed PC, ask IT before installing an optional update.
This topic is distinct from other same-KB bullets already covered elsewhere (e.g. RSA-3072 / PIV / minidriver, modernized AutoPlay, Family Safety, Smart App Control grayed out) — the angle here is only WSL2 / nested virtualization / AMD.
Confirmed points
- [Windows Subsystem for Linux (WSL)] group under normal rollout on KB5127936
- Fix: nested virtualization might not be available in WSL2 on AMD processors
- Non-security preview package dated October 28, 2026 for Windows 11 25H2 and 26H2 (builds 26200.9818 / 26300.9818)
- No invented hands-on lab; no invented AMD model list
Sources
Question: on your AMD machine (or fleet) with WSL2, did KB5127936 (or an equivalent preview) change anything for nested virtualization — without pasting sensitive dumps or attack scripts?