start-ssh-agent.cmd incompatible with OpenSSH 10.1+ security improvement (agent socket relocation)

[SvenStaehs]

Existing issues matching what you're seeing

• I was not able to find an open or closed issue matching what I'm seeing

Git for Windows version

git version 2.52.0.windows.1
cpu: x86_64
built from commit: 2912d8e9b8253723974b7baf1c890273b1a1c5bd
sizeof-long: 4
sizeof-size_t: 8
shell-path: D:/git-sdk-64-build-installers/usr/bin/sh
rust: disabled
feature: fsmonitor--daemon
libcurl: 8.17.0
OpenSSL: OpenSSL 3.5.4 30 Sep 2025
zlib: 1.3.1
SHA-1: SHA1_DC
SHA-256: SHA256_BLK
default-ref-format: files
default-hash: sha1

Windows version

Windows 11

Windows CPU architecture

x86_64 (64-bit)

Additional Windows version information

Microsoft Windows [Version 10.0.22631.6345]

Options set during installation

Editor Option: VIM
Custom Editor Path:
Default Branch Option:
Path Option: Cmd
SSH Option: OpenSSH
Tortoise Option: false
CURL Option: WinSSL
CRLF Option: CRLFAlways
Bash Terminal Option: MinTTY
Git Pull Behavior Option: Merge
Use Credential Manager: Enabled
Performance Tweaks FSCache: Enabled
Enable Symlinks: Disabled
Enable FSMonitor: Disabled

Other interesting things

No response

Terminal/shell

cmd

Commands that trigger the issue

cmd /C start-ssh-agent.cmd & cmd /C start-ssh-agent.cmd

Expected behaviour

Script finds existing ssh-agent socket even when called from another terminal (no SSH_AUTH_SOCK variable set)

Actual behaviour

Script reports failure and starts a new instance instead:

Found ssh-agent at 34908
Failed to find ssh-agent socket
Starting ssh-agent: done

Cause:
The script searches %TEMP%\ssh-* but OpenSSH 10.1+ creates sockets in %USERPROFILE%\.ssh\agent\.

Repository

No response