Microsoft has released Cumulative Update 7 (CU7) for SQL Server 2025, identified as KB5096981 and build 17.0.4065.4. According to the release notes, the update contains 10 fixes delivered after CU6 and updates both the SQL Server Database Engine and Analysis Services components.

The package is broad rather than narrowly targeted: it touches availability scenarios, query execution, JSON processing, security-related plumbing in the Universal Communication Stack, and Integration Services.

Known issues

Microsoft documents two known issues in this release:

  • SESSION_CONTEXT in parallel plans: Queries that use SESSION_CONTEXT can return incorrect results or produce access violation dump files when they run in parallel query plans, especially if the session is reset for reuse.
  • Linked server queries using MSDASQL: Linked server queries that use the MSDASQL provider and specify a provider string can fail with Msg 7416: “Access to the remote server is denied because no login-mapping exists.” Microsoft notes that stricter connection validation can reject some linked server configurations that previously worked.

The update notes also point readers to separate known-issues documentation for both behaviors.

Improvements and fixes

CU7 includes 10 verified fixes across several areas:

  • High availability and disaster recovery: A fix addresses intermittent Error 976 or Error 978 when monitoring queries using sys.dm_exec_requests or sys.sysprocesses run against a read-intent-only secondary replica in an availability group.
  • Universal Communication Stack: Several changes update or strengthen encryption behavior, including switching UCS encryption to AES-256 when TLS is not explicitly enabled and strengthening Service Broker dialog encryption with AES-256.
  • Programmability and JSON processing: Microsoft fixed a non-yielding scheduler condition tied to writing a time zone-related error to the error log, plus multiple JSON-related issues involving ALTER JSON INDEX REORGANIZE, JSON_MODIFY, JSON corruption, and dump files.
  • Query execution: The EDIT_DISTANCE function now has logical capping to prevent overflow errors that could otherwise lead to a denial-of-service crash.
  • Integration Services: The Message Queue task no longer supports the legacy BinaryMessageFormatter (2000 format), closing an insecure deserialization path related to untrusted MSMQ messages.
  • Windows-specific TLS management: SQL Server adds a trace flag that enables TLS 1.3 without editing the registry.

A few fixes stand out for practical planning: the JSON-related corrections, the availability-group monitoring fix, the EDIT_DISTANCE overflow protection, and the Integration Services deserialization change.

SQL Server 2025 CU7 also updates Analysis Services as part of the package, with the release notes listing refreshed component versions alongside the main Database Engine build.

Official source