NU1

Network	testnet
Released	Oct 4 2026
Activation height	16,529
Activated	About Oct 8 2026, 22:00 UTC

What changed

• RandomX security fix.
• RandomX v2 work. Adds the algorithm name rx/zecnero2. A third-party miner refers to it as rx2/zecnero.
• Native Windows mining binaries ship with this release.

TODO

Confirm the final algorithm name after NU1 and whether rx/zecnero2 is active on testnet or staged for a later upgrade. Confirm that native Windows binaries shipped with NU1. Confirm the protocol version after NU1 (180000 before).

TODO

Add a disclosure note for the RandomX security fix once it is safe to publish: what was affected and who needed to update.

If you missed it

A node or miner still on pre-NU1 software is on the wrong rules after block 16,529. Update:

zecnero-miner update

For nodes, see Keeping up with upgrades.