Microsoft has published Cumulative Update 1 (CU1) for SQL Server 2025 as KB5078298. The update brings 16 fixes across the engine, Linux, setup, connectivity, client tools, and search components, and it also documents one known issue involving SESSION_CONTEXT in parallel query plans.

The release updates SQL Server to 17.0.4006.2. Microsoft also lists an updated Analysis Services build alongside the database engine components.

Known issues

Microsoft documents one known issue in this release:

  • SESSION_CONTEXT in parallel plans: Queries that use the built-in SESSION_CONTEXT function might return incorrect results or trigger access violation dump files when they run in parallel query plans. Microsoft says this can happen because of how SESSION_CONTEXT interacts with parallel execution threads, especially if the session is reset for reuse.

Microsoft notes that removal of an item from the source would not by itself prove resolution, but in this packet the issue remains explicitly listed.

Improvements and fixes

CU1 contains 16 verified fixes. The changes are spread across several practical areas:

  • Engine programmability and DBCC: Fixes a DBCC CHECKDB WITH EXTENDED_LOGICAL_CHECKS issue that could stop responding and return an exception when a table contained both persisted and non-persisted computed columns with trace flag 176 enabled.
  • Connectivity and client tools: Fixes a crash in SQLCMD when using the -N switch in a :CONNECT command.
  • Linux engine behavior: Addresses several Linux-specific issues, including incorrect CPU usage metrics in sys.dm_os_ring_buffers, a failure when reading an invalid ID type from the Domain Controller, Active Directory login problems after a keytab update and privileged password rotation, incorrect time zone handling during Daylight Saving Time fall back, and unexpected memory exhaustion during VDI restore operations in cgroup-limited containers.
  • Security and diagnostics: Restricts dbcc stackdump so only sysadmin can invoke the dump file.
  • High availability and disaster recovery: Enables creating or restoring a database by using a listener for Container Availability Group Connection, allowing Contained AG users to create and restore without connecting directly to the SQL instance.
  • Resource Governor: Addresses a scenario where enabling traceflag 15918 through DBCC TRACEON on a server already started with traceflag 15923 could cause the SQL Server process to stop responding.
  • SQL OS and platform updates: Adds an informational error log message when deprecated lightweight pooling is enabled, and allows sys.fn_xe_file_target_read_file() to read system_health event session data in Azure SQL Managed Instance.
  • Search and full-text: Removes .rtf from full-text system DMVs on Linux, and fixes incorrect full-text index results for .docx files when a paragraph begins with a hyperlink and the previous paragraph has no trailing whitespace.
  • Setup and packaging: SQL Server 2025 can now be registered on Linux containers by setting MSSQL_PID to StandardDeveloper or EnterpriseDeveloper.
  • Configuration Manager: Fixes a hang in SQL Server Configuration Manager when importing a certificate.

Taken together, the release looks like a broad maintenance update rather than a single-area fix, with notable coverage for Linux deployments, search behavior, and operational tooling.

Official source