TL;DR — As of June 2026, the OpenSSL latest stable release is 4.0.1, published on 9 June 2026 as a security-patch release on the 4.0 branch. But "latest" isn't the same as "recommended for production": 4.0 is a feature release, not LTS. The current Long Term Support (LTS) release is the 3.5 series (latest patch 3.5.7), supported until 8 April 2030. If you want the newest code, run 4.0.x. If you want a stable, long-supported target, run 3.5.x. Always confirm the exact patch number on the official downloads page before you build.

If you searched for the OpenSSL latest stable release version in 2026, you probably expected a single number. The honest answer is two numbers, and knowing which one you need matters more than knowing which is highest. This guide gives you the current version for every supported branch, explains OpenSSL's versioning and support policy, and helps you pick the right release for your project. Everything below is grounded in OpenSSL's official library, corporation, and GitHub sources, with links at the end so you can verify.

What is the latest stable release of OpenSSL?

The latest stable release of OpenSSL is 4.0.1, published on 9 June 2026 as a security patch. It is the newest version overall, sitting on the 4.0 feature branch. Because 4.0 is not an LTS line, many teams instead target the 3.5 LTS series (3.5.7), which is supported far longer.

OpenSSL does not run a separate "unstable" channel for released versions. Every published release is production-grade; ongoing development happens in the git master branch and daily snapshots, which are explicitly not guaranteed to compile. So "latest stable release" simply means the newest published version — 4.0.1.

Latest OpenSSL versions by branch (June 2026)

OpenSSL maintains several branches at once, and each gets its own patch releases. Here are the current versions for every supported branch.

As of 2026-06-10 (last verified). Patch releases ship roughly every few weeks, so the trailing patch digit can move quickly. Verify the current numbers against the OpenSSL downloads page and the GitHub releases feed.

[VERIFY] note: The 4.0.1, 3.6.3, 3.5.7, and 3.4.6 patch numbers are confirmed from the 9 June 2026 GitHub release batch. The exact latest 3.0 patch (last confirmed 3.0.20) may have advanced in the same security cycle — check the downloads page.

Branches 3.3 and earlier (3.1, 3.2, 3.3) have reached end of life and should not be used. The legacy 1.1.1 and 1.0.2 series are out of general support and only receive fixes through commercial Extended Support.

Latest vs LTS: which OpenSSL version should you run?

This is the decision that actually matters, and it trips up a lot of developers. "Latest" and "best for me" are rarely the same version.

Run OpenSSL 4.0.x if you want the newest features

Choose the 4.0 series when you need the newest capabilities and can tolerate a shorter support window. OpenSSL 4.0 was the first major release since 3.0 in 2021, and it removed a lot of legacy surface area. Notable points:

• Dropped support for SSLv3 and the old ENGINE interface.
• Added Encrypted Client Hello (ECH, RFC 9849) support.
• Added post-quantum-adjacent work such as tls-hybrid-sm2-mlkem and the SM2 signature algorithm.
• Support ends 14 May 2027 — a relatively short runway for a major line.

Run OpenSSL 3.5.x (LTS) if you want stability

Choose the 3.5 series when you're shipping something you'll maintain for years. It's the current LTS, so it gets the longest support:

• Supported until 8 April 2030 (roughly four years of full fixes, then a final security-only year).
• The safest long-term target for distributions, appliances, and enterprise software.
• A second LTS, 4.2, arrives in April 2027, so there will always be two overlapping LTS lines to migrate between.

In short: greenfield or experimental → 4.0.x; long-lived production → 3.5.x LTS.

How OpenSSL version numbering works

Since 3.0, OpenSSL uses a MAJOR.MINOR.PATCH scheme that maps closely (but not identically) to semantic versioning. Understanding it tells you at a glance whether an upgrade is safe.

1. MAJOR (e.g. 3 → 4): API/ABI-incompatible changes. Code may need recompiling or edits.
2. MINOR (e.g. 3.5 → 3.6): New, backward-compatible features. Existing code keeps working.
3. PATCH (e.g. 3.5.6 → 3.5.7): Bug and security fixes only. No API/ABI breakage.

The key guarantee: API/ABI compatibility holds across the same MAJOR version. That's why moving from 3.4 to 3.6 is low-risk, but moving from 3.x to 4.0 needs a rebuild and testing. Before 3.0, OpenSSL used the old letter scheme (for example 1.1.1w or 0.9.8a), where the trailing letter marked patch releases.

What changed in OpenSSL 4.0

OpenSSL 4.0 landed on 14 April 2026 as the first major release in years, and it's aggressive about clearing technical debt. Beyond the SSLv3 and ENGINE removals above, it also:

• Removed the c_rehash script (use openssl rehash instead).
• Disabled deprecated elliptic curves and explicit EC curves at compile time by default.
• Added FFDHE key exchange for TLS 1.2 (RFC 7919) and SNMP/SRTP KDF support.
• Stopped libcrypto from cleaning up global data via atexit().

If you're upgrading from the 3.x line, read the release's CHANGES.md carefully — several of these are the kind of "potentially significant or incompatible" changes that break builds silently. The follow-up 4.0.1 patch then fixed a batch of CVEs plus two regressions in the openssl pkey and openssl s_client commands introduced in 4.0.0.

OpenSSL release schedule for 2026 and beyond

OpenSSL now ships on a predictable cadence: a feature release every six months (October) and a new LTS every two years (April). Here's the forward plan.

So the next release is 4.1 in October 2026, and the next long-term line is 4.2 in April 2027, followed by the 5.0 major release in October 2027. Planned dates are subject to change; treat anything past the current date as a target, not a promise.

How to check your installed OpenSSL version

To check which OpenSSL version you have, run the version command in your terminal:

openssl version

Typical output looks like OpenSSL 3.5.7 8 Apr 2026. For more detail, use these flags:

• openssl version -a — full build information, including the compile date and platform.
• openssl version -d — the OPENSSLDIR where configuration and certificates live.
• openssl version -v — just the version string.

One gotcha: the openssl command-line tool and the library your application links against can be different versions. To see what a program actually loads at runtime on Linux, inspect its dynamic dependencies (for example with ldd) rather than trusting the CLI alone.

A common misconception: "latest" is not always "recommended"

Here's the trap this article exists to defuse. Search engines and casual advice equate "latest OpenSSL version" with "the one you should install." OpenSSL's own model contradicts that.

Because OpenSSL deliberately alternates feature releases and LTS releases, the highest version number is frequently the short-lived one. In mid-2026, 4.0.1 is newest, yet 3.5's LTS support outlasts it by nearly three years. For anything you'll maintain, chasing the top number can leave you re-porting to a new major line sooner than necessary. Match the release to your maintenance horizon, not to the leaderboard.

Conclusion

To recap the OpenSSL latest stable release picture for 2026: the newest published version is 4.0.1 (9 June 2026) on the non-LTS 4.0 branch, while the recommended long-term target is the 3.5 LTS series (3.5.7), supported to April 2030. OpenSSL's MAJOR.MINOR.PATCH scheme and its six-month/two-year cadence mean the highest number and the most durable number are usually different — so choose based on how long you need support, not on which digit is biggest.

Next step: run openssl version to see what you're on, then cross-check the official OpenSSL downloads page for the exact current patch before you upgrade or build. Version numbers move fast; the download page is always the source of truth.

References

• OpenSSL Downloads — latest releases per branch (authoritative, verify latest patch here)
• OpenSSL GitHub Releases (4.0.1 published 9 June 2026)
• OpenSSL Corporation — Lifecycle & Release Plan (3.5 LTS to 8 Apr 2030; release schedule)
• OpenSSL 4.0 Final Release announcement (4.0 non-LTS, EOL 14 May 2027)
• OpenSSL Release Strategy & versioning policy (MAJOR.MINOR.PATCH rules)
• OpenSSL — Future release schedule (4.2 LTS Apr 2027, 5.0 Oct 2027)
• endoflife.date — OpenSSL (support-window summary)