# Protocol Buffers v36.1 — Protocol Buffers v36.1

- Product: Protocol Buffers (https://whatsnew.fyi/product/protobuf)
- Vendor: Google
- Date: 2026-08-31
- Version: v36.1
- Original notes: https://github.com/protocolbuffers/protobuf/releases/tag/v36.1
- Permalink: https://whatsnew.fyi/product/protobuf/releases/v36.1

What's New is an index, not a publisher: every entry below links to the vendor's own release notes, which are the authoritative source. Entries are labelled where they are hand-curated sample data, pre-releases, or drawn from a secondary source such as a developer blog.

Reuse: the summaries, labels and curation here are © What's New. Quote freely with attribution and a link back; wholesale republication of the corpus is not permitted — terms: https://whatsnew.fyi/terms. The vendors' own release notes remain their publishers'.

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- **changed** — Allow later enum aliases to overwrite in C# custom JSON enum mapping
- **changed** — Optimize pure Python parse path for custom JSON enum names
- **changed** — Include runtime version details in assertion error messages in Rust
- **removed** — Drop special treatment of Rust versions below 4.33
- **changed** — Invert the relationship between Rust crates
- **added** — Add additional unit tests for Python handling of custom JSON enum names

#### Announcements
* [Protobuf News](https://protobuf.dev/news/) may include additional announcements or pre-announcements for upcoming changes.

#### Csharp
* Allow later enum aliases to overwrite in C# custom JSON enum mapping. (https://github.com/protocolbuffers/protobuf/commit/cc7e6bd557dc9a9d4b984314d6456f2a3ad78570)

#### Rust
* Update README files for each crate. (https://github.com/protocolbuffers/protobuf/commit/e64a176925c0b1978bd6d14853605df384d60493)
* Include runtime version details in assertion error messages. (https://github.com/protocolbuffers/protobuf/commit/fecb404dc83e3f6fd0760fd1eb18332bddd701e9)
* Drop special treatment of rust versions below 4.33. (https://github.com/protocolbuffers/protobuf/commit/1312f3bb3d9f515b19e16f273f70d518b7cbba81)
* Invert the relationship between rust crates (https://github.com/protocolbuffers/protobuf/commit/fbf3069a7a29be3ecda2cea3455ec26895d3f81f)

#### Python
* Optimize pure Python parse path for custom JSON enum names. (https://github.com/protocolbuffers/protobuf/commit/333846acf4aec1392fdc15be64d12d6da3a220fd)
* Additional unit tests for Python handling of custom JSON enum names. (https://github.com/protocolbuffers/protobuf/commit/210324cac0f39d68db09d873afd23591255bf125)