v2.5.21

## v2.5.21

Release date: November 11, 2025

| Milvus version | Python SDK version | Node.js SDK version | Java SDK version |
|----------------|--------------------|---------------------|------------------|
| 2.5.21          | 2.5.17            | 2.5.13              | 2.5.14           |

We are excited to announce the release of Milvus 2.5.21, which addresses a **critical security vulnerability** [CVE-2025-64513](https://github.com/milvus-io/milvus/security/advisories/GHSA-mhjq-8c7m-3f7p) and we strongly encourage **all Milvus 2.5.x users to upgrade to 2.5.21** as soon as possible. This update also includes several other improvements and fixes, such as allowing nullable fields as BM25 function input field, and several performance enhancements.

### Improvements

- Supported use nullable field as bm25 function input field  ([#45118](https://github.com/milvus-io/milvus/pull/45118))
- Optimized the performance of bitmap reverse lookup  ([#44958](https://github.com/milvus-io/milvus/pull/44958))
- Implemented rewatch mechanism for etcd failure scenarios  ([#43920](https://github.com/milvus-io/milvus/pull/43920))
- Introduced sparse filter in query  ([#44790](https://github.com/milvus-io/milvus/pull/44790))
- Added accesslog field for template value length info  ([#44791](https://github.com/milvus-io/milvus/pull/44791))

### Bug fixes

- Avoided potential race conditions when updating the executor ([#45231](https://github.com/milvus-io/milvus/pull/45231))
- Skipped create tmp dir for growing r-tree index ([#45258](https://github.com/milvus-io/milvus/pull/45258))
- Fixed sort stats task failed when segment is compacting ([#45185](https://github.com/milvus-io/milvus/pull/45185))
- Supported skip load json stats when disabled ([#45098](https://github.com/milvus-io/milvus/pull/45098))
- Prevented data race in querycoord collection notifier update  ([#45052](https://github.com/milvus-io/milvus/pull/45052))
- Handled empty fieldsdata in reduce/rerank for requery scenario ([#44919](https://github.com/milvus-io/milvus/pull/44919))
- Fixed bug for gis function to filter geometry ([#44968](https://github.com/milvus-io/milvus/pull/44968))
- Fixed the geometry return point(0 0) when growing mmap is enabled ([#44891](https://github.com/milvus-io/milvus/pull/44891))
- Removed the limit of deduplicate case when disable autoindex ([#44782](https://github.com/milvus-io/milvus/pull/44782))
- Ensured deterministic search result ordering when scores are equal  ([#44885](https://github.com/milvus-io/milvus/pull/44885))
- Fixed deactivate balance checker also stops stopping balance ([#44835](https://github.com/milvus-io/milvus/pull/44835))
- Dropped segment in excluded segment use wrong excluded ts ([#44771](https://github.com/milvus-io/milvus/pull/44771))
- Avoided concurrent reset/add operations on datacoord metrics  ([#44817](https://github.com/milvus-io/milvus/pull/44817))