# Zebra 5.2.0: Wider Rollback Window

**URL:** <https://forum.zcashcommunity.com/t/zebra-5-2-0-wider-rollback-window/56279>\
**Category:** Zcash Foundation\
**Created:** [June 19, 2026, 4:23pm UTC](https://forum.zcashcommunity.com/t/zebra-5-2-0-wider-rollback-window/56279 "2026-06-19T16:23:15Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![ZcashFoundation](https://sea2.discourse-cdn.com/zcash/user_avatar/forum.zcashcommunity.com/zcashfoundation/32/21548_2.png) [@ZcashFoundation](https://forum.zcashcommunity.com/u/ZcashFoundation)\
**Post date:** [June 19, 2026, 4:23pm UTC](https://forum.zcashcommunity.com/t/zebra-5-2-0-wider-rollback-window/56279/1 "2026-06-19T16:23:15Z")

</div>

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](https://github.com/ZcashFoundation/zebra/pull/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 https://github.com/ZcashFoundation/zebra --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](https://zfnd.org) and the [Zebra repository](https://github.com/ZcashFoundation/zebra) for announcements.

## Contributors

Thank you to everyone who contributed to this release:

[@evan-forbes](https://github.com/evan-forbes), [@gustavovalverde](https://github.com/gustavovalverde), [@oxarbitrage](https://github.com/oxarbitrage), and [@upbqdn](https://github.com/upbqdn)

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Zebra is the Zcash Foundation’s independent, Rust-based implementation of the Zcash protocol. Learn more at [github.com/ZcashFoundation/zebra](https://github.com/ZcashFoundation/zebra).