# Heimdall v0.12.1

Announcements
1

Hello Node Operators,

We have released Heimdall v0.12.1 for both Mainnet and Amoy.

This release includes important security fixes, activated at the Lugano hardfork.

Source code is now public — see the GitHub release:

https://github.com/0xPolygon/heimdall-v2/releases/tag/v0.12.1

Lugano Activation Block

  • Mainnet: Block 54,627,000 — activated on 2026-10-01 at ~16:22 UTC

  • Amoy: Block 47,105,000 — activated on 2026-09-23 at ~19:32 UTC

Both networks have already passed their Lugano activation height.

Any operator still running a pre-Lugano binary should upgrade as soon as possible.

Steps to upgrade

  1. Stop heimdall service
sudo service heimdalld stop
  1. Install heimdall with a version tag, network name (mainnet or amoy), and node type (sentry, validator).
# Replace the network and node type
curl -L https://raw.githubusercontent.com/maticnetwork/install/heimdall-v2/heimdall-v2.sh | bash -s  v0.12.1 mainnet validator
  1. Check heimdall version
sudo /usr/bin/heimdalld version
# It should print
# 0.12.1
  1. Restart heimdall service
sudo service heimdalld start

Release Artifacts

GitHub Release: v0.12.1

https://github.com/0xPolygon/heimdall-v2/releases/tag/v0.12.1

What’s Changed

Full Changelog: v0.11.0…v0.12.1

Regards,

Polygon Team

2

Thanks for the clear upgrade steps. Since both networks have already passed the Lugano activation, the version check after the restart is a handy way for operators to confirm they are no longer running a pre-Lugano binary. It would be useful to see a short note on how operators can confirm the node is following the upgraded chain after the restart.