Release Notes for v25.3-v25.3.6 (#21566)

Author: release-notes-automation[bot]

src/current/_data/releases.yml

@@ -10041,6 +10041,41 @@
   previous_release: v26.1.0-alpha.1
 
 
+- release_name: v25.3.6
+  major_version: v25.3
+  release_date: '2025-12-12'
+  release_type: Production
+  go_version: go1.25.3
+  sha: 86392cec66fd0b9851358fa76a6f0aac1d691a84
+  has_sql_only: true
+  has_sha256sum: true
+  mac:
+    mac_arm: true
+    mac_arm_experimental: true
+    mac_arm_limited_access: false
+  windows: true
+  linux:
+    linux_arm: true
+    linux_arm_experimental: false
+    linux_arm_limited_access: false
+    linux_intel_fips: true
+    linux_arm_fips: false
+  docker:
+    docker_image: cockroachdb/cockroach
+    docker_arm: true
+    docker_arm_experimental: false
+    docker_arm_limited_access: false
+  source: true
+  previous_release: v25.3.5
+  cloud_only: true
+  cloud_only_message_short: 'Available only for select CockroachDB Cloud clusters'
+  cloud_only_message: >
+      This version is currently available only for select
+      CockroachDB Cloud clusters. To request to upgrade
+      a CockroachDB self-hosted cluster to this version,
+      [contact support](https://support.cockroachlabs.com/hc/requests/new).
+
+
 - release_name: v25.2.10
   major_version: v25.2
   release_date: '2025-12-12'

src/current/_includes/releases/v25.3/v25.3.6.md

@@ -0,0 +1,35 @@
+## v25.3.6
+
+Release Date: December 12, 2025
+
+{% include releases/new-release-downloads-docker-image.md release=include.release %}
+
+<h3 id="v25-3-6-bug-fixes">Bug fixes</h3>
+
+- A mechanism that prevents unsafe replication changes from causing loss of quorum now functions correctly. An internal function has been fixed to properly return errors, enhancing the reliability of replication safeguards. [#156522][#156522]
+- Fixed a bug where the "atomic" `COPY` command (controlled via the `copy_from_atomic_enabled` session setting, `true` by default) could encounter `RETRY_COMMIT_DEADLINE_EXCEEDED` transaction errors if the whole command took 1 minute or more. This bug occurred only when the vectorized engine was used for `COPY`. [#156694][#156694]
+- Attempting to create a vector index with the legacy schema changer will now fail gracefully instead of crashing the node. [#156781][#156781]
+- Fixed a bug that could cause internal errors for queries using generic query plans with `NULL` placeholder values. [#156978][#156978]
+- Fixed a bug where CockroachDB could encounter an internal error when evaluating a `COPY FROM` command in a transaction after it was rolled back to a savepoint. The bug was present since before v23.2. [#157038][#157038]
+- Fixed a bug where CockroachDB could encounter a `vector encoder doesn't support ForcePut yet` error when executing `COPY` commands concurrently with certain schema changes. The bug had existed since before v23.2. [#157199][#157199]
+- Fixed a bug that could cause a schema change to be stuck in the reverting state if the `infer_rbr_region_col_using_constraint` storage parameter was being set at the same time as adding a constraint that had a foreign key violation. [#157843][#157843]
+
+<h3 id="v25-3-6-performance-improvements">Performance improvements</h3>
+
+- The cost of generic query plans is now calculated based on worst-case selectivities for placeholder equalities (e.g., `x = $1`). This reduces the chance of suboptimal generic query plans being chosen when `plan_cache_mode=auto`. [#156791][#156791]
+
+<h3 id="v25-3-6-miscellaneous">Miscellaneous</h3>
+
+- Span config reconciliation jobs no longer fail on the
+  destination after failover from a PCR stream of a system virtual cluster. [#156811][#156811]
+
+
+[#156791]: https://github.com/cockroachdb/cockroach/pull/156791
+[#156781]: https://github.com/cockroachdb/cockroach/pull/156781
+[#156978]: https://github.com/cockroachdb/cockroach/pull/156978
+[#157038]: https://github.com/cockroachdb/cockroach/pull/157038
+[#157843]: https://github.com/cockroachdb/cockroach/pull/157843
+[#156522]: https://github.com/cockroachdb/cockroach/pull/156522
+[#156694]: https://github.com/cockroachdb/cockroach/pull/156694
+[#157199]: https://github.com/cockroachdb/cockroach/pull/157199
+[#156811]: https://github.com/cockroachdb/cockroach/pull/156811