Microsoft has released SQL Server 2022 Cumulative Update 23 (CU23), also tracked as KB5078297. The update raises SQL Server 2022 to build 16.0.4236.2 and includes 15 fixes issued after CU22.

The release spans several areas that DBAs and developers are likely to recognize immediately: backup and restore, high availability, connectivity, Linux-specific behavior, query execution, and certificate handling in SQL Server Configuration Manager. Microsoft also documents one known issue involving SESSION_CONTEXT in parallel query plans.

Known issues

Microsoft says queries that use the built-in SESSION_CONTEXT function might return incorrect results or generate access violation (AV) dump files when they run in parallel query plans. The issue is tied to how SESSION_CONTEXT interacts with parallel execution threads, especially if the session is reset for reuse.

Improvements and fixes

CU23 contains 15 verified fixes. The changes are spread across the engine and related components:

  • Backup and restore: fixes a backup log failure that could report that BACKUP LOG is not allowed while the recovery model is SIMPLE.
  • High availability and disaster recovery: addresses an AV assertion in DbMgrPartner related to new log readiness notifications, fixes Distributed Availability Group seeding when the local Availability Group is offline, and changes long availability group names created with cluster_type = NONE or EXTERNAL to return error 19544 instead of an assert.
  • Connectivity and protocols: fixes non-yielding scheduler dump files that can appear when SSL connections are closed under high CPU load.
  • Programmability and query execution: addresses a hang during the SQL Server 2019 to SQL Server 2022 upgrade at the model database phase, fixes a crash caused by a missing partition in a common table expression (CTE), and corrects AppDomains that remain in a DOOMED state.
  • Linux-specific fixes: resolves a crash related to an invalid ID type returned from the Domain Controller in LookupAccountSid, fixes Active Directory logins when the keytab file is updated too long after privileged password rotation, and addresses a memory allocation failure during VDI restore operations when cgroupsv2 limits memory.
  • Security infrastructure: fixes a failure to configure multiple concurrent auditing for the Security Event log during updates and restricts dbcc stackdump so only sysadmin can invoke the dump file.
  • SQL Server Configuration Manager: fixes certificate import failures involving certain self-signed password-protected certificates and certificates exported from Azure AKV without passwords.
  • SQL OS / Azure SQL Managed Instance: allows sys.fn_xe_file_target_read_file() to read system_health event session data in Azure SQL Managed Instance.

Microsoft also notes a change in behavior for long availability group names and a privilege restriction for dbcc stackdump, which are operational changes rather than standard bug fixes.

If you are tracking SQL Server 2022 servicing, CU23 is the post-CU22 update to review for this mix of engine, platform, and management fixes.

Official source