OpenSSL 4.1 Alpha Release Announcement

Sep 9, 2026

The OpenSSL Project is pleased to announce that OpenSSL 4.1 Alpha1 pre-release is available, which adds significant new functionality to the OpenSSL Library.

OpenSSL 4.1.0 is a feature pre-release adding significant new functionality, bug fixes and mitigations. This release incorporates the following potentially significant or incompatible changes:

• Added VC-WIN32-MSVC2013 and VC-WIN64A-MSVC2013 build targets to provide internal functions for bridging the gaps in C99 standard support that are present in MSVC 2013.

• Added optimized ML-DSA and ML-KEM NTT operations on ppc64le; optimized ML-DSA operations on s390x, and x86_64; AVX-512-optimized SHAKE x4 operations for ML-DSA on x86_64; AVX-512 and VAES optimizations for AES-CBC decryption on x86_64.

• Changed tsget utility to use Net::Curl::Easy (from the Net-Curl CPAN distribution) instead of the abandoned WWW::Curl::Easy. Users who rely on tsget should install Net::Curl::Easy before upgrading.

• Dropped Windows-on-Itanium (VC-WIN64I) and Windows CE (VC-CE) targets from Configurations.

• Dropped no-ecdsa and no-ecdh options from Configure, as these options did not really disable the implementations. Use no-ec to disable the elliptic curve support.

This release adds the following new features:

• Support for DTLS 1.3 (RFC 9147). Refer to the ossl-guide-dtlsv13(7) manual page for details.

• Support for RFC 8701 GREASE (Generate Random Extensions And Sustain Extensibility).

• DTLS support in the SSL listener API.

• Support for IKEV2 KDF.

• Initial support for the Elbrus2000 (e2k) architecture.

Note: this pre-release has been provided for testing ONLY. It should NOT be used for security critical purposes. To report a bug, please open an issue on GitHub.

You can download the Alpha release from our download page or from the GitHub release page