SQL Server 2025 CU1 Fixes the Docker Desktop AVX Issue on macOS

Good news for anyone who’s been working around the AVX issue I wrote about in my previous post. Microsoft has fixed it in Cumulative Update 1 (CU1) for SQL Server 2025.

What Changed

Back in November when SQL Server 2025 RTM was released and I upgraded to macOS 26, I ran into an AVX instruction issue that prevented the container from starting on Docker Desktop using Rosetta on Apple Silicon. The container would crash with this error:

SQL Server 2025 will run as non-root by default.
This container is running as user mssql.
To learn more visit https://go.microsoft.com/fwlink/?linkid=2099216.
assertion failed [x86_avx_state_ptr->xsave_header.xfeatures == kSupportedXFeatureBits]: 
(ThreadContextSignals.cpp:414 rt_sigreturn)

The workaround is to use OrbStack instead of Docker Desktop since OrbStack has better x86_64 emulation support, including AVX instructions.

CU1 to the Rescue

With the release of CU1, Microsoft has resolved this issue. The container now starts successfully on Docker Desktop without needing any workarounds. Here’s what I tested today on my Mac running macOS Tahoe 26.1 with Docker Desktop 4.58.1.

First, let’s confirm the RTM issue still exists. Running the RTM image on Docker Desktop:

docker run -e "ACCEPT_EULA=Y" -e "MSSQL_SA_PASSWORD=<password>" \
   -p 1434:1433 --name sql-rtm --hostname sql-rtm \
   -d \
   mcr.microsoft.com/mssql/server:2025-RTM-ubuntu-22.04

Still crashes with the same AVX error. This confirms the fix hasn’t been backported to the RTM release.

Now let’s start up a container using the CU1 image:

docker run -e "ACCEPT_EULA=Y" -e "MSSQL_SA_PASSWORD=<password>" \
   -p 1433:1433 --name sql1 --hostname sql1 \
   -d \
   mcr.microsoft.com/mssql/server:2025-CU1-ubuntu-24.04

This time, the container starts cleanly. Here’s what the logs show:

SQL Server 2025 will run as non-root by default.
This container is running as user mssql.
To learn more visit https://go.microsoft.com/fwlink/?linkid=2099216.
2026-02-02 11:15:32.50 Server      Microsoft SQL Server 2025 (RTM-CU1) (KB5078298) - 17.0.4006.2 (X64) 
	Jan 22 2026 18:05:52 
	Copyright (C) 2025 Microsoft Corporation
	Enterprise Developer Edition (64-bit) on Linux (Ubuntu 24.04.3 LTS) <X64>
...
2026-02-02 11:15:34.39 Server      CPU vectorization level(s) detected:  SSE SSE2 SSE3 SSSE3 SSE41 SSE42 AVX AVX2 POPCNT BMI1 BMI2
...output omitted...
2026-02-02 11:16:02.09 spid38s     SQL Server is now ready for client connections. This is an informational message; no user action is required.

In the output above, you’ll see SQL Server starts up happily and it’s detecting AVX and AVX2 instructions now.

What About RTM?

The fix has not been backported to the RTM image (2025-RTM-ubuntu-22.04) and the others. If you need to run the RTM version specifically on Docker Desktop for macOS, you’ll still need to use OrbStack as a workaround mentioned in my previous post.

Wrapping Up

If you’ve been using OrbStack as a workaround like I have, you can now switch back to Docker Desktop with CU1 if that’s your preference.