Next long-term support release?


I was wondering if there was any thinking or planning around when the next LTS (long term support) branch (post 2.7.x) will be released?


Hi Brent,
As you may know, we don’t publicly publish our roadmap and schedule, so I can’t commit on any date of when it will be released.
Note that version 2.7.6 has been released about a month ago, so there weren’t too many changes since, on the LTS.
Is there a specific reason you are waiting for next release? Is there a specific bug fix you are interested in?
I am quite sure though, that the next release will be by end of December, but I can’t commit to that.
I know this is not the answer you were looking for, but this is the best i can give.
Thank you for your interest in Mbed TLS!
Mbed TLS team member


Thanks for the fast response. I fully understand the policy of not publishing roadmap info on the forum. We have a similar policy where I work as well :slight_smile:

First, some background info on my question. We have a substantial code base that uses Mbed TLS for (some of) its crypto functionality. We supply our code base as a combination of static libraries and source for others to use as a base and add their own applications on top of. Furthermore, we provide access to Mbed TLS so they can implement their own security features independently of the functionality that our code is using, all sharing the same acceleration hardware.

The inertia that we have with our code base and that our partners have in theirs makes us good candidates for an LTS build. We can track the maintenance releases of 2.7.x fairly easily. As we assemble new release candidates, we can pull in the latest 2.7.x, regression test, QA and publish because of the limitation on API and functionality changes.

However, we also like new features and want to be able to extend our capabilities. But integrating new feature branches is expensive work. We’re happy to do it because we deem it is worth it, but we would like to be able to plan for it by allocating resources, etc.

I think what you have answered above is that “2.7.7” (which is the next release of the latest 2.7.x LTS branch) will be released by the end of December. That’s good to know, but it’s not the main question I’m interested in. What I meant to ask is what is the next feature branch that will be promoted to LTS after 2.7.x (for example, it might be 2.16.1)? Or approximately when would that be released (for example, it might be February 2019, or Q2 2020)?

Even knowing a coarse time frame is helpful, as that enables us to pull the latest feature branch a couple of months earlier and start regression testing against it and working out the kinks so that when LTS is released, we have a smaller amount of work remaining to complete the integration.

There are examples of open source code bases that issue feature releases at a regular cadence: Ubuntu tends to release LTS versions in April of even years (2016, 2018, 2020, etc.), and Eclipse tends to release LTS main versions annually in June, for example. This might be something to consider, particularly as the adoption of Mbed TLS continues to grow.

Again, I understand if this is not a question you can answer (or can’t answer here). However, even a blog post a few months or weeks beforehand would be helpful.

My dream is to see a blog post by Simon B saying, “We are thinking about another LTS release in a couple of months. What do you think about this? We’d love to hear your feedback. Let us and other users of the library know your views through the Mbed TLS forum.”

Thanks again, and best regards,


Hi Brent,
We usually have one feature branch release, based on the development branch, and two LTS releases. They are released st the same time.
If you look at the latest release’ release notes, you will see:

End of life for Mbed TLS 2.1
Mbed TLS 2.1.0 was first shipped on 4th September 2015, and is nearing the end of its life. Mbed TLS 2.1 will not be supported after Autumn 2018. All users of Mbed TLS 2.1 are advised to upgrade to a later version of Mbed TLS wherever possible. The latest long-term support branch is Mbed TLS 2.7.

This basically means that we will soon have a new LTS branch replacing 2.1.
I recommend you follow the new releases and the release note, to see what LTS branches are nearing their end. This will give you some idea of new LTS releases. You can also follow them on our github repository.
You can also follow our blog. We try to declare there new LTS branches as well.
I hope this answers your question.
Mbed TLS Team member

Thank you. This is perfect!

Best regards,