# RabbitMQ v4.3.5 — RabbitMQ 4.3.5 - Product: RabbitMQ (https://whatsnew.fyi/product/rabbitmq) - Vendor: Broadcom - Date: 2026-08-17 - Version: v4.3.5 - Original notes: https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.5 - Permalink: https://whatsnew.fyi/product/rabbitmq/releases/v4.3.5 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'. --- - **fixed** — With direct reply-to, a message routed to multiple targets that resolved to the same process could be delivered to it more than once - **fixed** — Quorum queue recovery from a recovery checkpoint could leave a part of the queue's internal state only partially initialized - **fixed** — In clusters that run a mix of 4.2.x and 4.3.x nodes during a rolling upgrade, local quorum queue queries now fall back to the previous state machine version instead of failing - **fixed** — A malformed AMQP 1.0 frame now results in a framing error returned to the client instead of an exception - **fixed** — The AMQP 1.0 message parser now validates message sections more strictly and decodes certain types of arrays more efficiently - **fixed** — Topic exchanges now limit the number of multi-segment wildcards a binding key can use to two - **fixed** — When connection credentials are refreshed, the user's tags are now updated instead of being carried over from the original state - **fixed** — Definition import from an HTTPS endpoint no longer fails when a password-protected TLS client certificate is used - **fixed** — The AMQP 1.0 Erlang client no longer logs an exception when a link is already detached - **added** — Authentication events are now logged under a new logging category, user, with successful logins at the info level and failed login attempts at the warning level - **added** — rabbitmqctl hash_password now supports more password hashing functions - **fixed** — A stream protocol connection that attempts to exceed 256 publishers or 256 subscriptions is now rejected early with a clear error - **added** — Before a stream client connection completes authentication and authorization, the server now enforces a low frame_max ceiling with a default of 8192 bytes, configurable via the stream.initial_frame_max setting - **added** — New setting stream.max_uncompressed_sub_entry_batch_size bounds the declared uncompressed size of a published sub-entry batch with a default of 67108864 bytes - **fixed** — HTTP API endpoints that accept a node name now validate that the target node is a cluster member - **fixed** — The management UI no longer displays certain alert messages twice RabbitMQ `4.3.5` is a maintenance release in the `4.3.x` [release series](https://www.rabbitmq.com/release-information). It is **strongly recommended** that you read [4.3.0 release notes](https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.0) in detail if upgrading from a version prior to `4.3.0`. ###### Minimum Supported Erlang Version The minimum supported Erlang version for this release series is `27.0`. [RabbitMQ and Erlang/OTP Compatibility Matrix](https://www.rabbitmq.com/docs/which-erlang) has more details on Erlang version requirements for RabbitMQ. Nodes **will fail to start** on older Erlang releases. ##### Changes Worth Mentioning Release notes can be found on GitHub at [rabbitmq-server/release-notes](https://github.com/rabbitmq/rabbitmq-server/tree/v4.3.x/release-notes). ###### Core Server ###### Bug Fixes * With [direct reply-to](https://www.rabbitmq.com/docs/direct-reply-to), a message routed to multiple targets that resolved to the same process could be delivered to it more than once. GitHub issue: [#17071](https://github.com/rabbitmq/rabbitmq-server/pull/17071) * Quorum queue recovery from a recovery checkpoint could leave a part of the queue's internal state only partially initialized. GitHub issue: [#17012](https://github.com/rabbitmq/rabbitmq-server/pull/17012) * In clusters that run a mix of `4.2.x` and `4.3.x` nodes during a rolling upgrade, local quorum queue queries now fall back to the previous state machine version instead of failing. GitHub issue: [#17128](https://github.com/rabbitmq/rabbitmq-server/pull/17128) * A malformed AMQP 1.0 frame now results in a framing error returned to the client instead of an exception. GitHub issue: [#17101](https://github.com/rabbitmq/rabbitmq-server/pull/17101) * The AMQP 1.0 message parser now validates message sections more strictly and decodes certain types of arrays more efficiently. GitHub issue: [#17049](https://github.com/rabbitmq/rabbitmq-server/pull/17049) * Topic exchanges now limit the number of multi-segment (`#`) wildcards a binding key can use to two. The `#` wildcard is meant to be used as the final segment, that is, just once. GitHub issue: [#17039](https://github.com/rabbitmq/rabbitmq-server/pull/17039) * When connection credentials are refreshed (for example, when an [OAuth 2](https://www.rabbitmq.com/docs/oauth2) token is renewed), the user's tags are now updated instead of being carried over from the original state. GitHub issue: [#17029](https://github.com/rabbitmq/rabbitmq-server/pull/17029) * [Definition import](https://www.rabbitmq.com/docs/definitions#import-on-boot) from an HTTPS endpoint no longer fails when a password-protected TLS (HTTPS) client certificate is used. Contributed by @Pyolar. GitHub issue: [#16973](https://github.com/rabbitmq/rabbitmq-server/pull/16973) * The AMQP 1.0 Erlang client no longer logs an exception when a link is already detached. Workloads that use short lived links could produce a substantial amount of log noise. GitHub issue: [#17124](https://github.com/rabbitmq/rabbitmq-server/pull/17124) ###### Enhancements * Authentication events are now logged under a new logging category, `user`. Successful logins are logged at the `info` level, failed login attempts at the `warning` level. GitHub issue: [#16907](https://github.com/rabbitmq/rabbitmq-server/pull/16907) ###### CLI Tools ###### Enhancements * `rabbitmqctl hash_password` now supports more password hashing functions. GitHub issues: [#14215](https://github.com/rabbitmq/rabbitmq-server/issues/14215), [#17108](https://github.com/rabbitmq/rabbitmq-server/pull/17108) ###### Stream Plugin ###### Bug Fixes * A stream protocol connection can have at most 256 publishers and 256 subscriptions, a limit that comes from the protocol's wire format. _[Truncated at 4000 characters — full notes: https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.5]_