News | Azure Local 2605

Microsoft has released Azure Local 2605 (solution version 12.2605.1003.210, OS build 26100.32860, available date 2026-05-28). The detailed feature list is not on the What’s New page yet, but the release is significant for an operational reason: it is the build that closes out the unintended Azure Local VM deletion incident, and it is what unblocks Solution and SBE updates across the fleet.

What we know today

• Solution version: 12.2605.1003.210.
• OS build: 26100.32860.
• Availability date: 2026-05-28.
• May OS security update applied.
• New deployments now use 12.2605.1003.210.

Why this release matters for operators

• Microsoft resolved the issue that could cause unintended Azure Local VM deletion. Manual remediation guidance was shared earlier for affected clusters, and a new Telemetry & Diagnostics Arc extension auto-remediated the majority of remaining clusters via managed update.
• Solution and SBE updates are unblocked again with 2605 in place.
• Microsoft also shipped same-day hotfixes for 2603 and 2604: 12.2603.1002.502 and 12.2604.1003.1006. These add a second layer of automated VM deletion remediation as you update into those versions.

Update paths (important for upgrade planning)

• On 2510 through 2602: discover and apply 12.2603.1002.502 or later first.
• On 2603: discover and apply 12.2604.1003.1006 or later.
• On 2604: discover and apply 12.2605.1003.210.
• 2601 and 2602 are no longer valid update targets. If you are running them today you remain supported, but you cannot use them as a target for new updates. Move to 2603 or later.

Known issues

Microsoft has not yet published a Known Issues section for 2605. The 2604 carry-over items still apply in the meantime, most notably:

• Windows Admin Center Cluster Manager below 5.2.6 can cause issues during volume deletion, with risk of data loss. Update to 5.2.6 or WAC 2511 build 2.6.6.18 or higher before deleting any volume.
• Defender ASR rule “Block Process Creations originating from PSExec & WMI” set to Block breaks Solution Update. Adjust before running an update.
• az stack-hci-vm stop on CLI 1.14.x against pre-2604 clusters: use --skip-shutdown or downgrade to CLI 1.13.0.
• Mochostagent service can appear running but stop updating logs: check C:\programdata\mochostagent\logs and restart with restart-service mochostagent.

Release information: https://learn.microsoft.com/azure/azure-local/release-information-23h2?view=azloc-2605