Avoid quadratic failed response size when failure store redirects fail #162017 (issue: #157859)
Show the effective index mode and settings of the next backing index in GET _data_stream, and honor settings that a request explicitly unsets. #161250 (issue: #125685)

Distributed

Handle IndexShardClosedException and shutdown in ReplicationOperation::updateCheckPoints #162378 (issue: #158303)

Downsampling

ES|QL

Bind ES|QL lookup requests to their target shard #162521
Cache output #161282
Catch REPLACE regex StackOverflowError #157957
Circuit-break before growing the array #160592
Ensure Lucene operator status is immutable #161190 (issue: #160823)
Fix IN pushdown on ip, version, unsigned_long, date fields #161455
Fix CASE with a single-value list condition, and report multivalued conditions with the standard single-value function encountered multi-value warning #157956
Fix InferIsNotNull #155172 (issue: #155101)
Fix MvPercentile precision on edge cases and unmute tests #145996 (issues: #145888, #162784, #145889, #162778, #145886, #162782, #145887, #162780)
Fix case-insensitive empty term query on wildcard fields #161726
Fix vector builder memory accounting #163376
Keep AsyncOperator blocked after finish #162486
Push down SORT _score ASC as ascending #160651 (issue: #160650)
Release empty percentile digest when the breaker trips #162147

Highlighting

Fix inference field highlighting when values come from direct assignment and copy_to #161156 (issue: #159964)

Inference

[Inference API] Add support for thought signature for Gemini 3.x models #160167 (issue: #159760)

Infra/Core

Infra/Scripting

Machine Learning

Fix NPE in datafeed delayed data check #163732
Propagate rest status #163386
Skip unready stats indices in cleanup #163140 (issues: #162947, #162417, #152311, #162939, #147656, #159566)

Mapping

Packaging

Reindex

Search

Bound the input in boolean and ip parse errors #163033
Bound the input in date parse errors #162994
Bound the query in query_string parse errors #162886
Deduplicate terms lookup fetches and apply max_terms_count during rewrite #159241
Fork top_hits fetch context once per aggregator #159231 (issue: #158722)
Improve memory usage in ConcurrentSegmentSourceProvider #162158
Improve memory usage in ConcurrentSegmentSourceProvider #162483
Release scroll contexts when index removed #161556 (issue: #161316)
Return 400 when an intervals query rule expands to too many terms #162833 (issue: #162297)
Skip the index sort range query optimization on indices with nested fields #162658

Security

Apply fls to constant_keyword in new and reindexed percolate queries at runtime #162302 (issue: #161396)
Fix deadlock in Microsoft Graph authz realm token acquisition #161254 (issue: #161197)
Reject node enrollment unless the HTTP leaf chains to the pinned CA and is within its validity period #160525
Verify API key before decoding cross-cluster info #161492

Suggesters

Fix _search error when the suggest_field URL parameter is set without suggest_mode #163107 (issue: #162301)

TLS

Fix intermittent TLS handshake failures on aarch64 caused by a JDK race (JDK-8393730) #161141 (issue: #160280)

TSDB

Reject rollover migrating a data stream from a non-standard index mode to TSDB #161992 (issue: #161905)

Templates

Transform

Fix continuous transforms not deleting old checkpoints from .transform-internal-* (causing the index to grow without bound) while their node’s host has been up between about 107 and 214 days, and deleting checkpoints newer than the 10-day retention period at other times #162048 (issue: #161960)
Honor GetCheckpoint timeout on node transport requests and add settings.indexer_request_timeout #157746 (issue: #157745)