Windows: ssh-keyscan get `choose_kex: unsupported KEX method sntrup761x25519-sha512@openssh.com`

[Chindada]

Description

Run ssh-keyscan github.com >> "$env:USERPROFILE\.ssh\known_hosts" fail on windows-latest or windows-2025

Platforms affected

• Azure DevOps
• GitHub Actions - Standard Runners
• GitHub Actions - Larger Runners

Runner images affected

• Ubuntu 22.04
• Ubuntu 24.04
• macOS 13
• macOS 13 Arm64
• macOS 14
• macOS 14 Arm64
• macOS 15
• macOS 15 Arm64
• macOS 26 Arm64
• Windows Server 2019
• Windows Server 2022
• Windows Server 2025

Image version and build link

Current runner version: '2.328.0'
Runner Image Provisioner
Operating System
Runner Image
Image: windows-2025
Version: 20250907.19.1
Included Software: https://github.com/actions/runner-images/blob/win25/20250907.19/images/windows/Windows2025-Readme.md
Image Release: https://github.com/actions/runner-images/releases/tag/win25%2F20250907.19

Is it regression?

https://github.com/mold-link/mojave-web/actions/runs/17785431035/job/50552179816

Expected behavior

ssh-keyscan completly without error.

Actual behavior

github.com:22 SSH-2.0-550beff

choose_kex: unsupported KEX method sntrup761x25519-sha512@openssh.com

github.com:22 SSH-2.0-550beff

choose_kex: unsupported KEX method sntrup761x25519-sha512@openssh.com

github.com:22 SSH-2.0-550beff

choose_kex: unsupported KEX method sntrup761x25519-sha512@openssh.com

github.com:22 SSH-2.0-550beff

choose_kex: unsupported KEX method sntrup761x25519-sha512@openssh.com

github.com:22 SSH-2.0-550beff

choose_kex: unsupported KEX method sntrup761x25519-sha512@openssh.com

Repro steps

run ssh-keyscan -v github.com

[hemanthmanga]

Hi @Chindada, Thank you for bringing this issue to our attention. We will look into this issue and will update you after investigation.