SQL Server 2022 Cumulative Update 25 (KB5081477) is documented as build 16.0.4255.1 and includes 12 fixes after Cumulative Update 24. The update spans the Database Engine, Integration Services, and SQL Server Client Tools, so it is broader than a single-component patch.

It also carries forward two documented known issues, one involving SESSION_CONTEXT in parallel plans and another affecting linked server queries that use MSDASQL with a provider string.

Known issues

Microsoft lists two known issues for CU25:

  • Incorrect behavior of SESSION_CONTEXT in parallel plans: Queries that use SESSION_CONTEXT might return incorrect results or trigger access violation dump files when run in parallel query plans, especially if the session is reset for reuse.
  • Linked server queries that use MSDASQL fail with error 7416: Linked server queries that use the MSDASQL provider and specify a provider string can fail with Msg 7416, Level 16 Access to the remote server is denied because no login-mapping exists. Microsoft notes that a stricter connection validation check can reject certain linked server configurations that earlier builds allowed.

Improvements and fixes

CU25 includes 12 verified fixes. The changes are concentrated in a few practical areas:

  • Availability and mail delivery: Fixes a Database Mail issue in Contained Availability Groups where messages could be sent without attachments. It also addresses Contained Availability Group connection behavior and related restrictions for DBCreator roles.
  • Upgrade and management metadata: Fixes a problem where permissions on stored procedures and other msdb objects could be lost during SQL Server upgrade.
  • Query processing and memory use: Fixes a memory leak tied to parallel execution of SHORTEST_PATH queries in graph databases, which caused persistent OBJECTSTORE_SOSTASK growth.
  • Storage and data integrity: Fixes a self-assignment update issue on a small off-row XML column with compression enabled that could lead to XML corruption and a subsequent transport-level error when selecting the data. It also fixes an error seen when online index operations run alongside DML in databases with Change Data Capture (CDC) enabled.
  • Platform-specific engine fixes: Addresses an access violation when querying sys.dm_xe_session_targets on Windows Server 2025, and a Linux backup cleanup issue that could leave SQL Server unresponsive when a network share becomes full or unreachable.
  • Integration Services: Fixes issues involving the Oracle ODBC driver and the ODBC connector, including heap corruption and data loss scenarios in SSIS packages. CU25 also fixes an XXE issue in the Web Service Task by blocking file:// in WSDL service endpoints.
  • In-memory OLTP: Adds yields during garbage collection scans of hash indexes to address CPU starvation.

A few representative bug references from this release include 4954485, 4999187, 5034739, 5090699, 5126699, 5131000, 5157137, and 5213660.

If you track SQL Server 2022 servicing closely, CU25 is mainly about tightening up edge cases across engine behavior, upgrade handling, integration workflows, and platform-specific execution paths, while also documenting two existing known issues for planning and triage.

Official source