Zcash Foundation rolls out Zebra security patches ahead of NU7 upgrade

The security patches target specific weaknesses that allowed peers to stall synchronization, consume verification resources, or trigger node crashes. Among the high-severity issues, the foundation identified two checkpoint synchronization failures and vulnerabilities related to costly signature calculations and inefficient transaction checks. While these flaws impacted network availability, the foundation confirmed that no invalid blocks were written to disk and user funds remained secure throughout the affected period.

Operators must complete the transition before the network hits block 3,543,405 to maintain consensus. Upgrading to Zebra 7.0.0 triggers a database migration from format v28 to v29; because this change is irreversible, developers advise backing up the existing state directory before proceeding. The update also introduces technical shifts for monitoring systems, as peer metrics no longer include specific address and user-agent labels.

Beyond security, the NU7 upgrade implements ZIP 218, which reduces block target times from 75 seconds to 25 seconds. To address performance concerns raised by miners during the Zcon7 conference, the foundation also released an alpha version, 7.1.0-alpha.0, dubbed Zebra Ándale. This iteration significantly optimizes template creation, reducing the time required to process transaction bursts from over eight minutes to roughly four seconds.