We have recently released Zebra 5.2.0. This release ships a robustness improvement that was merged to main after the 5.1.1 maintenance release: a significantly wider local rollback window to defend against consensus splits.
All node operators are encouraged to upgrade. Nodes running Zebra 5.1.1 or earlier will reach end-of-support on approximately July 25, 2026, ahead of the expected NU7 network upgrade.
New Features
Wider local rollback window (MAX_BLOCK_REORG_HEIGHT 99 → 1000)
Zebra’s local rollback window — the maximum number of non-finalized tip blocks Zebra will retain in memory, ready to reorganize — has been increased from 99 to 1000 blocks (#10650).
This is a defense-in-depth measure motivated by real-world incidents on other chains. A reorg window of 99 blocks covers roughly 99 minutes at Zcash’s one-block-per-75-seconds pace. A 1000-block window provides coverage for reorgs of up to approximately 20 hours, giving node operators and network participants substantially more time to respond to a sustained consensus split.
This change is the primary reason for the minor-version bump: MAX_BLOCK_REORG_HEIGHT is a public constant exported by zebra-chain, and its value changed ten-fold, affecting both memory usage (the non-finalized state may now hold up to 1000 blocks in RAM instead of 99) and any downstream consumers that import the constant directly.
Upgrading
To upgrade to Zebra 5.2.0, install it with:
cargo install --git --tag v5.2.0 zebrad
Or update via your package manager if you are using a pre-built binary.
Zebra 5.2.0 nodes will stop around July 25, 2026, approximately 37 days after the estimated release height. We plan to release a further update ahead of the expected NU7 network upgrade. Keep an eye on the Zcash Foundation blog and the Zebra repository for announcements.
Contributors
Thank you to everyone who contributed to this release:
@evan-forbes, @gustavovalverde, @oxarbitrage, and @upbqdn
Zebra is the Zcash Foundation’s independent, Rust-based implementation of the Zcash protocol. Learn more at github.com/ZcashFoundation/zebra.