Host key verification failed. fatal: Could not read from remote repository.
SSH doesn’t trust the server’s host key — first connection in a non-interactive environment, or the key changed.
Seen on:
Git
Meaning
CI/Docker builds have an empty known_hosts, and GitHub rotated its RSA host key in March 2023, causing “REMOTE HOST IDENTIFICATION HAS CHANGED” for old entries.
Common causes
- First SSH connection in CI/Docker (no known_hosts)
- Stale known_hosts entry after a host key rotation
- Man-in-the-middle (rare, but verify)
⚡ Quick fix
- Add the host key: ssh-keyscan github.com >> ~/.ssh/known_hosts (verify fingerprints)
- Remove stale entries: ssh-keygen -R github.com
Detailed fix by platform
Git
ssh-keygen -R github.com && ssh -T git@github.com
How to diagnose
- Known hosts — Entry present? Changed?
- Recent change — Did it start after a deploy, upgrade, or configuration change? Compare with the last working version.
🧠 Still stuck? Analyze your error
Paste the full message, response headers or stack trace — we'll detect the platform and point to the most likely cause.
Was this page helpful?
Report a correction or suggest an improvement
Last updated 2 Oct 2026