Linkerd Edge Release Roundup: August 2025

Welcome to the August 2025 Edge Release Roundup post, where we dive into the most recent edge releases to help keep everyone up to date on the latest and greatest! This post covers edge releases from June and July 2025.

How to give feedback

Edge releases are a snapshot of our current development work on main; by definition, they always have the most recent features but they may have incomplete features, features that end up getting rolled back later, or (like all software) even bugs. That said, edge releases are intended for production use, and go through a rigorous set of automated and manual tests before being released. Once released, we also document whether the release is recommended for broad use – and when needed, we go back and update the recommendations.

We would be delighted to hear how these releases work out for you! You can open a GitHub issue or discussion, join us on Slack, or visit the Buoyant Linkerd Forum – all are great ways to reach us.

Community contributions

We couldn’t do what we do without the Linkerd community, and this batch of releases is definitely no exception. Huge thanks to Carlos Martell, Jonas Dittrich, Wim de Groot, and joedrf for their contributions! You’ll find more information about all of these contributions in the release-by-release details below.

Recommendations and breaking changes

We recommend that everyone running an edge release go straight to edge-25.7.6. If you can’t run that version for some reason, check out edge-25.7.4.

The reason for this unusually blunt recommendation is that edge-25.7.4 fixes a bug that could cause Linkerd to use more memory than it should when dealing with a lot of HTTP/1 connections, and we’d really like everyone to benefit from that fix… and since edge-25.7.6 adds some more features on top of that, we think it’s a good idea to go straight to that version.

As always, we have a couple of breaking changes to note:

As of edge-25.7.1, Linkerd will refuse connections to a Service port that isn’t listed in the Service’s spec.ports, which mirrors Kubernetes’s behavior without Linkerd and should help avoid surprises.
In edge-25.6.3, we changed the histogram buckets for gRPC handling-time histograms. The previous buckets were optimized for short-lived streams, where Linkerd’s controllers typically use much longer-lived streams. The updated bucket sizes are much better suited to the longer lifetimes.
Also in edge-25.6.3, we updated the port names used in many Linkerd deployments to avoid Kubernetes 1.33’s new warnings if port names aren’t unique across all containers in the same pod:
- In destination, grpc becomes dest-grpc and admin-http becomes dest-admin
- In sp-validator, admin-http becomes spval-admin
- In policy-controller, grpc becomes policy-grpc and admin-http becomes policy-admin
- In identity, grpc becomes ident-grpc and admin-http becomes ident-admin
- In proxy-injector, admin-http becomes injector-admin
- In linkerd2-cni, admin-http becomes repair-admin

The releases

As always, each edge release includes many dependency updates which we won’t list here. You can find them in the full release notes for each release.

edge-25.7.6 (July 31, 2025)

This release is recommended for all users, and is most likely the one you should run if you’re reading this post.

This release supports percentages, as well as integers, when setting the maxUnavailable field in the podDisruptionBudget in Helm values (thanks, Wim de Groot!), cleans up the descriptions for some proxy metrics (thanks, joedrf!), produces auditable binaries for the policy controller and proxy, and prefers AES algorithms over ChaCha20 for mTLS. It also correctly performs reproducible builds, fixing issue #13873.

edge-25.7.5 (July 23, 2025)

This release contains internal improvements, but no new capabilities over edge-25.7.4. As such, we recommend that you skip it and go straight to edge-25.7.6!

edge-25.7.4 (July 17, 2025)

This release is recommended for all users.

This release contains a fix to reduce the proxy’s memory usage when handling many HTTP/1 connections.