Support for MsQuic

An MsQuic release begins its life in the main branch where it receives feature updates as well as servicing for security and bug fixes. When it is time to release, the code will be forked into a release branch where it is considered stable and will generally only receive servicing for security and bug fixes.

MsQuic Branches

MsQuic has two main types of branches main and release defined as:

Main - Main is the primary development branch, and receives security and bug fixes just the same as the release branches. However, the main branch is where active development happens and because of this the main branch may experience breaking changes as we develop new features.
Release - Release branches only receive security and bug fixes, and are considered stable. There should be no breaking changes in these branches, and they can be used for stable products.
- Prerelease - The Releases section below indicates which releases are considered officially supported and serviced releases. All others are considered prereleases, which are generally considered stable, but will not receive servicing fixes.

* Both main and official release branches receive critical fixes throughout their lifecycle, for security, reliability.

Release Support Policies

MsQuic support lifecycle is governed by the Windows Server servicing channels: LTSC and SAC

LTSC indicates official release branches to be serviced for 5 years mainstream and 5 years extended.
SAC indicates official release branches to be serviced for 18 months.
PRE indicates prerelease branches (not officially supported).
TBD indicates release branches that are set to be classified as one of the above.

Important Main is not considered officially supported. It is under active development (i.e. not stable), however it does receive security and bug fixes.

End of support

End of support refers to the date when Microsoft no longer provides fixes, updates, or online technical assistance for your product. As this date nears, make sure you have the latest available update installed. Without Microsoft support, you will no longer receive security updates that can help protect your machine from harmful viruses, spyware, and other malicious software that can steal your personal information.

Releases

A release branch will be created (forked) for each release of MsQuic. Official release branches will then go through a several month stabilization process before it is then finalized. Once finalized, offical release branches will only be serviced with security and bug fixes throughout its lifecycle. MsQuic official releases generally will correspond to Windows releases, but in some cases additional future releases may be created for other major products. Official releases for Windows generally will end support at the same time as the Windows release.

This table describes all officially supported MsQuic releases.

Type	Branch	Consumer	Fork Date	Release Date	End of Support	Supported Platforms
SAC	release/2.1	.NET 7	Aug 5 2022	Oct 5 2022	Apr 5 2024	Windows, Linux
SAC	release/2.2	Windows Server 2022 Windows 11	Apr 18 2023	June 1 2023	Dec 1 2024	Windows, Linux
SAC	release/2.3	Windows Server 2025 Windows 11	Jan 26 2024	Mar 12 2024	Sept 12 2025	Windows, Linux

* Future Release Dates are subject to change.
** End of Support dates do not include possible extended support extensions.

Publishing a Release

Create a New Release Branch

Add (via PR) notes above for the new release.
Fork main branch to release/X.Y where X is the major version and Y is the minor version.
Update (via PR) the minor version for the main branch:
- Run ./scripts/update-version.ps1 -Part Minor to generate the relavent changes.
- Also add the new version to the bug_report.yaml issue template file.

Servicing a Release Branch

Changes first go into the main branch, and then are cherry-picked into the relavent release/X.Y branches.
Update (via PR) the patch version for the release branches:
- Run ./scripts/update-version.ps1 -Part Patch to generate the relavent changes.

Publishing a Release Branch

Create a new GitHub release along with the corresponding tag.
- Make sure to pick the correct release/X.Y branch
- The tag should be the full version number: vX.Y.Z
- The release title should be MsQuic vX.Y.Z
- Put relavent information in the notes of the release (see previous releases for examples)
Wait for msquic-Official pipeline to run for the newly created tag.
Download the signed Linux packages (under drop_package_linux_distribution), upload them to the GitHub release and publish them (via MsQuic-Publish) to https://packages.microsoft.com:
- libmsquic-X.Y.Z-1-aarch64.rpm
- libmsquic-X.Y.Z-1-armhf.rpm
- libmsquic-X.Y.Z-1-x86_64.rpm
- libmsquic-X.Y.Z-amd64.deb
- libmsquic-X.Y.Z-arm64.deb
- libmsquic-X.Y.Z-armhf.deb
Download the signed Windows NuGet packages (under drop_package_windows_nuget) and upload them to NuGet:
- Microsoft.Native.Quic.MsQuic.OpenSSL.X.Y.Z.BUILD.nupkg
- Microsoft.Native.Quic.MsQuic.Schannel.X.Y.Z.BUILD.nupkg
- Use https://raw.githubusercontent.com/microsoft/msquic/vX.Y.Z/README.md as package description URL.
Wait for msquic-Official-Tests pipeline to run for the newly created tag.
Download the distribution packages from the artifacts and upload them to the GitHub release:
- msquic_gamecore_console_x64_Release_schannel.zip
- msquic_linux_x64_Release_openssl.zip
- msquic_linux_x64_Release_openssl_test.zip
- msquic_windows_arm64_Release_openssl.zip
- msquic_windows_arm64_Release_schannel.zip
- msquic_windows_arm_Release_openssl.zip
- msquic_windows_arm_Release_schannel.zip
- msquic_windows_x64_Release_openssl.zip
- msquic_windows_x64_Release_schannel.zip
- msquic_windows_x64_Release_schannel_test.zip
- msquic_windows_x86_Release_openssl.zip
- msquic_windows_x86_Release_schannel.zip
The macOS distribution package isn't generated from the internal pipelines. Grab it from the public CI from the latest run of the release branch (under distribution), and upload it to the GitHub release:
- msquic_macos_universal_Release_openssl.zip
From Linux (use GitHub Codespace) to publish the latest Rust Crate.
- Run cargo publish from the release/X.Y branch.
Update (via PR) main branch's test-down-level.yml to point the newly uploaded *_test.zip release binaries.

Synchronizing with Windows

Once the release branch is created, set the pipeline here to ingest the release branch into Windows, and run it.
When the pipeline passes tests, it'll create a PR.
Review and merge the PR to complete the process.

MsQuic v1.0 (LTSC)

MsQuic v1.0 is the first officially supported release. The primary shipping vehicle for this release will be the Windows Server 2022 release. No official, signed binaries are currently slated to be released. Linux support is considered a preview for this release.

The QUIC specifications are currently "Submitted to IESG for Publication", so both the v1 and draft-29 versions are supported by this release.

Important QUIC protocol features not fully implemented:

0-RTT

Client-side Migration

Server Preferred Address

Path MTU Discovery

Known Issues

GetParam for QUIC_PARAM_CONN_STATISTICS does not populate Handshake.* fields.

MsQuic v1.1 (SAC)

MsQuic v1.1 has various small improvements from v1.0. The primary shipping vehicle for this release will be the Windows 11 client release. These changes include:

Preview support for Version Negotiation extension.
Public API header build fixes.
Improved certificate validation APIs.
OpenSSL certificate validation fixes.
Added (off by default) SSLKEYLOGFILE support.
Linux datapath bug fixes and improvements.
Various CI improvements around performance testing; including TCP comparison support.
Diagnostics documentation improvements.

The QUIC specifications have been approved by the IESG and are in RFC editor queue. Both the v1 and draft-29 versions are supported by this release.

Known Issues

GetParam for QUIC_PARAM_CONN_STATISTICS does not populate Handshake.* fields.

MsQuic v1.2 (Prerelease)

Not officially supported

MsQuic v1.2 has numerous improvements from v1.1. As this is a prerelease, there is no expected shipping vehicle for this release. Some noted changes in this release include:

Switched to quictls (https://github.com/quictls/openssl) and the 1.1.1 branch of OpenSSL instead of 3.0
Initial MacOS support added (using OpenSSL)
Support for RSS, GSO and Receive Batching on Linux
Initial OpenSSL session resumption and 0-RTT support
Improved CPU and WAN performance
Various API improvements (e.g. new delayed send API flag; query handshake info)
Initial client certificate support with Schannel on Windows
Initial support for ACK frequency (or delayed ACK) QUIC extension
Support for pkcs12 imports

The QUIC specifications are still in RFC editor queue. Both the v1 and draft-29 versions are still supported by this release.

MsQuic v1.3 (Prerelease)

Not officially supported

MsQuic v1.3 has numerous improvements from v1.2. As this is a prerelease, there is no expected shipping vehicle for this release. Some noted changes in this release include:

Removed old/unused mitls and stub TLS providers. Only schannel and openssl are officially supported (#1398, #1411).
Fully support Resumption and 0-RTT with OpenSSL (#1469).
Fully support Windows UWP apps (#1429, #1452, #1454).
Support Client certificate validation (#1366).
Support ChaCha20-Poly1305 with OpenSSL (#1431).
Support Cipher Suite allow-list (#1430).
Support Portable Certificate verification (#1450).
Various performance improvements (tune recv pkt queue, worker partition ID for send, UDP send queuing) (#1424, #1448, #1451, #1456, #1474, #1483).
Fixed SO_REUSEPORT perf issue on server sockets (Linux only) (#1391).
Fixed various issues with macOS (arm platform detection, max CPU count) (#1388, #1427).
Fixes bugs that causes stream to get in (temporary) bad state when aborting receive path (#1513, #1516).
Update StreamShutdown to run inline on callbacks (#1521).
Support universal binaries for macOS (#1414).
Added/updated documentation, especially around trouble shooting (#1423, #1467, #1481, #1486).
Refactored/improved WPA plugin and cmd line tool, QuicTrace (#1482, #1484, #1485, #1490, #1493, #1499).

The QUIC specifications are being actively looked at by the RFC editor. Both the v1 and draft-29 versions are still supported by this release.

MsQuic v1.4 (Prerelease)

Not officially supported

MsQuic v1.4 has numerous improvements from v1.3. As this is a prerelease, there is no expected shipping vehicle for this release. Some noted changes in this release include:

Updated User Mode PGO.
Perf improvement from sent packet metadata stream ref counting (#1529).
Support address sanitizer on Windows.
Random allocation test support for SpinQuic and BVT (#1537, #1541).
Fix key phase and key update detection logic (#1548).
Fixed bug with stateless reset and retired CIDs (#1568).
Add support for Peer Accept Stream event (#1560).
Various bug fixes found from random allocation failure tests.
Various additional test cases added.
Added multiple API version support.
Lots of improved documentation.
Enabled ACK frequency in CPU limited scenarios (#1588).
Support for DPLPMTUD (#1563).
Reduced min MTU to 1248 (#1673).
Refactored POSIX error codes (breaking change for POSIX, #1645).

The QUIC specifications now offically RFC. Both the v1 and draft-29 versions are still supported by this release.

MsQuic v1.5 (Prerelease)

Not officially supported

MsQuic v1.5 is a prerelease so there is no expected shipping vehicle. Some noted changes in this release include:

Windows Kernel client certificate support (#1652).
Added load balancer app (#1696) and automated testing (#1707).
Fixed a bug for QUIC_SETTING size validation logic (#1724).
Added support for local UDP port sharing (Linux only) (#1751).
Switched Param Id's to not be overlapping (#1758).
Refactored library load (#1748) and added static linking support (Windows only) (#1446).
Fixed bug around handshake idle timeout (#1780).
Added support for stream prioritization (#1778).
Fixed bug when shutting connection down during the handshake (#1797).
Improved testing around path changes and few minor bug fixes (#1783, #1801).
Improved event callback reentrancy to reduce app complexity (#1802).
Fixed bug related to sharing abort code for stream send/recv shutdown (#1809).
Fixed bug related to queuing 0-RTT during the handshake (but after start) (#1817).
Use root level certificate verification callback in OpenSSL (#1818).
Ignore Duplicate Stream Read Shutdowns (#1822).
Constrain processor index to processor count on posix (#1824).
Build speed and build dependency improvements (#1845) (#1839).
Initial support for Android binaries (#1835).
Update version negotiation to draft v4 (#1826).
Fix issues where datapaths and sockets might be used incorrectly (#1843) (#1837).
Various documentation improvements and additions.