MC1276259 Medium Major change

Windows Deployment Services (WDS): Hands-free deployment hardening (Phase 2)

  • Admin
  • Security

Summary AI-generated

Starting April 2026, hands-free deployment in Windows Deployment Services is disabled by default to enforce security for CVE-2026-0386; override requires registry change.

Suggested actions AI-generated

  • Override secure default with registry setting to retain hands-free deployment (not recommended)
  • Plan migration to alternative deployment solutions
  • Review hardening guidance for CVE-2026-0386

Written by Azure OpenAI (gpt-4.1) from the text of the post below. It can be incomplete or wrong; the original post is authoritative.

Original post from Microsoft

As announced in January 2026, the unattend.xml file used in hands‑free deployment poses a vulnerability when transmitted over an unauthenticated RPC channel. Beginning with the April 2026 security update, the second phase of hardening for CVE-2026-0386 is now in effect. These changes make hands‑free deployment disabled by default to enforce secure behavior. After this update, hands‑free deployment no longer works unless explicitly overridden with registry settings.

When will this happen:
Starting with the April 2026 security update, Windows Deployment Services (WDS) enforces secure‑by‑default behavior by automatically disabling hands‑free deployment.

How this will affect your organization:
After installing the April 2026 security update, hands‑free deployment is blocked to prevent unauthenticated access to unattend.xml, enforcing the hardening requirements for CVE-2026-0386. Any workflows that rely on unattend.xml‑based deployment will no longer function unless overridden with registry settings.

What you need to do to prepare:
Organizations that still require hands‑free deployment after installing the April 2026 security update must explicitly override the secure default by setting the AllowHandsFreeFunctionality registry value to 1, which keeps unattend.xml‑based deployments operational but reintroduces the security risks associated with CVE-2026-0386. When this override is used, devices will log diagnostic messages indicating that they are operating in an insecure mode. Because this configuration is not recommended for long‑term use, IT admins should plan to migrate to alternate deployment solutions and return to secure‑by‑default behavior.

Additional information: