Zcash Sets NU7 Mainnet Height at 3,543,405 as Zebra Tackles Sync Stalls

Developers have formally assigned the mainnet activation block for the Zcash Network Upgrade 7 (NU7) at height 3,543,405, targeting activation around Nov. 5, 2026, according to a merged repository pull request ². The approval also fixes the mainnet Non-Sprout-to-Non-Sprout (NSM) reissuance height at 8,939,664 under ZIP 237 and sets the conclusion height for Revision 2 funding streams at 6,132,390 in ZIP 214 ².

While protocol specifications are finalized, client teams are moving to resolve infrastructure bottlenecks before stable rollouts ¹. The Zcash Foundation opened an epic tracking readiness for Zebra 7.0.0 stable, documenting several node synchronization stalls observed on the public testnet ¹. The NU7 upgrade previously activated on the public testnet at block 4,465,026 on about Oct. 6, 2026, but network tests revealed issues where nodes stopped syncing or tracked losing chain branches during min-difficulty bursts ¹.

Client Readiness and Node Fixes

According to the Zebra tracking document, the network seeder fleet has not yet confirmed consensus on the testnet, reporting only 14 of 31 peer groups ready against a required 75% quorum ¹. Zebra engineers are evaluating fixes for open issues, including near-tip sync stalls caused by busy serving peers, early cache evictions of transparent outpoints, and honest peers being mistakenly banned over lock-time rejections ¹. Three security fixes in a private repository are also queued for inclusion in Zebra 7.0.0 ¹.

At the time of writing, $ZEC traded at $1,258, up 11.0% over 24 hours. The upgrade will enforce critical changes, including the migration and deprecation procedures outlined in earlier protocol drafts. Node operators, wallet recovery tools, and institutions that recently updated infrastructure must ensure compatibility before mainnet block 3,543,405 arrives ^{1 2}.