Linkerd Blog

Welcome to the excessively-large December 2025 Edge Release Roundup posts, 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 September through November 2025 (the runup to KubeCon was hectic around here).

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.

Today we’re happy to announce Linkerd 2.19! This release introduces a significant state-of-the-art security improvement for Linkerd: a modernized TLS stack that uses post-quantum key exchange algorithms by default.

Linkerd has now seen almost a decade of continuous improvement and evolution. Our goal is to build a service mesh that our users can rely on for 100 years. To do this, we partner with users like Grammarly to ensure that Linkerd can accelerate the full scale and scope of modern software environments—and then we feed those lessons directly back into the product. Linkerd 2.19 release is the third major version since the announcement of Buoyant’s profitability and Linkerd project sustainability a year ago, and continues our laser focus on operational simplicity—delivering the notoriously complex service mesh feature set in a way that is manageable, scalable, and performant.

This blog post was originally published on Matthew McLane’s Medium blog.

I’ll start by saying that I think Linkerd is a great tool. We use it at work to provide TLS between our pods, which frees us from having to build that functionality directly into our containers. When it works, it’s fantastic! It’s simple to get up and running and just does the job without a lot of extra fuss. For the most part, it’s been a very hands-off experience, which is exactly what we need.