Avalanche's Helicon upgrade set a hard mainnet deadline and moved every node to plugin version 46
Victoria Shinder1 min readThe avalanchego release page carries the operational detail behind Avalanche's Helicon network upgrade. The release that schedules it states the activation time plainly — 11 AM ET, 3 PM UTC, Tuesday 22 September 2026 on Mainnet — and states the obligation just as plainly: all mainnet nodes must upgrade before that time. The same release bumps the plugin version to 46, and all plugins must match.
The page also shows the shape of the pipeline behind it. Helicon appears as a Fuji pre-release under the subtitle "Continuous Execution and Auto-Renewed Staking", alongside Granite, described as improving ICM and dynamic block times, also on Fuji. The testnet line and the mainnet line are visibly separate, with the Fuji builds carrying the feature descriptions and the mainnet release carrying the schedule.
What it means
The plugin version bump is the part that decides how painful an upgrade day actually is. A network upgrade with a fixed activation time is a coordination problem, and the failure mode is not the consensus change, it is an operator who updated the node binary and left a virtual machine plugin at the previous version. Requiring all plugins to move to 46 makes that mismatch explicit rather than letting it surface as a node that runs and then diverges.
The two names on the Fuji line are worth keeping separate in one's head. Continuous execution and auto-renewed staking is a validator-economics change; improving ICM and dynamic block times is a throughput and cross-chain messaging change. They are travelling through the testnet at the same time, which means an operator reading release notes needs to know which of the two is already binding on mainnet and which is still ahead — a distinction the release page makes if you read the tags rather than the titles.