Zcash Prepares for NU7 Upgrade as Zebra Gets Key Security Fixes

The Zcash network is moving closer to its NU7 upgrade following a series of Zebra releases focused on security, performance and network stability.

According to an engineering update from the official Zcash Foundation X account covering September 21 through October 5, developers released four Zebra versions. Three belonged to the 6.4.x series, while the fourth was the first release candidate for Zebra 7.0.0.

Zebra is the Zcash Foundation’s independent full-node implementation for the Zcash blockchain, built from scratch using the Rust programming language.

Zebra 6.4.0 introduced several important improvements, including security fixes, an experimental lightwalletd-compatible gRPC server and a lower ZIP 317 conventional transaction fee. The release also accelerated block template delivery for miners and moved the end-of-support halt forward as the network prepares for NU7.

Zebra 6.4.1, released the same day, addressed a potential synchronization stall near the blockchain’s tip. Developers later issued Zebra 6.4.2 as an emergency update after discovering that a malformed transaction sent by any network peer could trigger a crash. The vulnerability was identified through Google’s OSS-Fuzz service, which tests open-source software with randomized inputs.

Attention has now shifted toward NU7. Zebra 7.0.0-rc.0, the upgrade’s first release candidate, activated on the Zcash public Testnet at block 4,465,026 on October 4. The Testnet rollout gives developers and users an opportunity to evaluate NU7 before its planned mainnet deployment.

Another Zebra release supporting NU7 is expected before Zebra 6.4.1 reaches its end-of-support halt around November 2. Mainnet operators will need to upgrade before the 6.4.x series stops operating in early November. NU7 mainnet activation is tentatively scheduled for November 5, 2026.

Meanwhile, Zcash’s native ZEC token was trading at $1,376, up 2.93% over 24 hours but below its September 26 high of $1,696. Whale accumulation has continued despite the pullback, with Lookonchain reporting that a newly created wallet recently withdrew 7,166 ZEC from Coinbase.