Zcash NU7 upgrade risks freezing legacy Sprout funds

CoinTelegraph reported that a proposed change to Zcash’s NU7 network upgrade could render funds in the legacy Sprout shielded pool unspendable. The risk stems from the upgrade’s plan to disable version 4 transactions, which would cut off access to ZEC held in that specific shielded environment.

The NU7 update is designed to improve the network’s performance and security standards, but the removal of version 4 transaction support creates a specific liability for long-term holders. Any Zcash deposited in the older Sprout pool relies on that legacy transaction type for spending. If the network deprecates the format without a migration path, those assets would effectively be locked away.

Holders are advised to verify their wallet versions and shielded pool status before the upgrade activates. The distinction matters because standard transparent balances are unaffected, while legacy shielded funds require proactive movement to the current Sapling or Orchard pools to remain liquid. The change targets obsolete cryptographic structures, leaving modern holdings untouched.