Zebra 6.0.0-rc.0 Launch – Zcash Basis

Zebra 6.0.0-rc.0: NU6.3 “Ironwood” Help and Safety Fixes

We’re happy to announce the discharge of Zebra 6.0.0-rc.0. This launch candidate provides Testnet help for the NU6.3 “Ironwood” shielded pool and v6 transaction format, fixes two moderate-severity safety points, ships signed pre-built zebrad binaries for Linux, and features a state database format improve. All node operators are inspired to check it on Testnet forward of the ultimate 6.0.0 launch.

Safety Advisories

GHSA-x6v8-c2xp-928m: getblock Verbosity 2 Facet-Chain Panic (Reasonable)

The getblock RPC at verbosity 2 panicked for blocks not on the very best chain: their transactions’ confirmations are destructive and had been forged to an unsigned sort, crashing the node. The repair adjustments the confirmations subject to a signed sort, matching zcashd and the remainder of Zebra’s codebase.

Because of Taylor Hornby for reporting this problem.

GHSA-m9xx-8rcj-vmgp: Per-Peer Mempool Admission Cap Bypass (Reasonable)

Zebra caps concurrent inbound mempool admissions per peer, however the cap solely utilized to marketed transaction IDs. Instantly pushed transactions (tx messages) bypassed it, letting a single inbound peer occupy greater than its share of obtain slots by pushing full transactions as a substitute of promoting them. This launch routes straight pushed transactions by way of the identical per-peer admission accounting. It’s the direct-push counterpart to the advertisement-path repair shipped in GHSA-4fc2-h7jh-287c.

Because of SuplabsYi of Invariant Labs for reporting this problem.

New Options

NU6.3 “Ironwood” Help (Testnet)

Zebra now helps the NU6.3 “Ironwood” shielded pool and the v6 transaction format, activating on Testnet at peak 4,134,000. The consensus parameters: v6 model group ID, consensus department ID, and Testnet activation peak, match zcash_protocol. No Mainnet activation peak is ready but. The z_gettreestate, z_getsubtreesbyindex, and verbose getblock RPCs expose the Ironwood notice dedication tree and its subtree roots from NU6.3 activation. (#10762, #10888)

Coinbase Marker for Zebra-Mined Blocks

Zebra now tags the coinbase enter of each block it mines with a 🦓. Consequently, the mining.extra_coinbase_data possibility is now restricted to 86 bytes (beforehand 94); Zebra refuses to begin if the configured worth exceeds this. (#10836)

Pre-Constructed, Signed zebrad Binaries

Pre-built zebrad binaries at the moment are hooked up to every GitHub launch for Linux on x86_64 and aarch64, so operators can run a node with out Docker or a supply construct. Binaries are additionally installable with cargo binstall zebrad. Every .tar.gz carries a SHA-256 checksum, a Sigstore build-provenance attestation, and a Cosign signature over the checksum manifest. (#10799)

Block Notify Command

A brand new [notify] block_notify_command possibility runs a command on every best-chain-tip change, with %s changed by the brand new block hash: Zebra’s equal of zcashd‘s –blocknotify. (#10726)

Resumable Indexer Streaming

When the indexer RPC is enabled, a co-located read-state shopper can now observe the node extra effectively: the non-finalized block subscription resumes from the buyer’s identified chain suggestions as a substitute of re-streaming the entire non-finalized state, and a brand new GetBlock indexer methodology lets the buyer fetch blocks it’s lacking whereas its finalized state catches up. A brand new zebra-state learn request, ReadRequest::FindForkPoint, returns the latest block in a caller-supplied locator that’s on the very best chain, the fork level, for shoppers monitoring chain reorganizations by way of a read-only state service. (#10776)

Regtest Coinbase Spend Restrictions

A brand new Regtest configuration possibility, should_allow_unshielded_coinbase_spends, forbids spending coinbase outputs into clear outputs: the inverse of zcashd‘s –regtestshieldcoinbase. It defaults to permitting such spends, preserving present Regtest conduct. (#10698)

Bug Fixes

Sync Stall Close to the Chain Tip

A timeout ready for a clear enter UTXO throughout transaction verification is now handled as a lacking enter fairly than an inner error, stopping a sync stall close to the chain tip. (#10810)

getblocktemplate Coinbase Caching

getblocktemplate now caches the constructed coinbase transaction per block, so repeated short-poll requests inside the similar block now not rebuild it. This prevents CPU saturation and multi-second template latency when mining to a shielded deal with. (#10847)

Indexer Syncer Subscription Churn

The co-located read-state syncer (utilized by indexers like Zaino) now not drops and re-creates its non-finalized block subscription each second whereas its view of the finalized state lags the node’s. (#10818)

invalidateblock / reconsiderblock Edge Circumstances

Fastened edge circumstances in invalidateblock and reconsiderblock (chain-root and same-height sibling-tip invalidation, and repeated reconsideration) that might trigger a panic. (#10586)

Modified

State Database Format Improve to twenty-eight.0.0

The state database format is bumped to 28.0.0 for the NU6.3 “Ironwood” shielded pool. This can be a major-version bump that’s restorable in place from the earlier main format (no resync required): an in-place migration backfills the genesis Ironwood notice dedication tree and anchor, creates 4 new (initially empty) ironwood_* column households, and widens the chain worth pool file to incorporate the Ironwood pool. The getblockchaininfo and getblock valuePools now embody the ironwood pool, which might be at zero till NU6.3 prompts.

Different Modifications

• Upgraded the librustzcash crate cohort to the NU6.3 pre-release wave for V6 transactions and Ironwood help. (#10762)
• Bumped anyhow to 1.0.103, clearing RUSTSEC-2026-0190. (#10849)
• Opening a Zebra state read-only now fails with a transparent error as a substitute of panicking when the cache listing is lacking or unreadable, when no database exists on the configured path, or when an ephemeral database can also be configured. The read-write open path is unchanged.

Different Safety Enhancements

• Zebra’s launch Docker photos at the moment are reproducible: an impartial rebuild of a printed zebrad from the identical commit produces the identical binary. The Rust toolchain and the Rust and Debian base photos are pinned by actual model and digest, and construct paths and file timestamps are normalized. Launch photos are additionally constructed with out the shared construct cache, so a printed picture can’t inherit a layer from a lower-trust construct. (#10798)
• Launch Docker photos are signed and carry construct provenance and a signed SBOM, so anybody can verify a picture got here from Zebra’s CI with cosign confirm or gh attestation confirm. (#10798)
• Zebra now makes use of a constant-time comparability for RPC cookie authentication. (#10567)
• Launched zebrad binaries report their supply commit in zebrad model. (#10798)

Upgrading

This can be a launch candidate meant for Testnet testing forward of the ultimate 6.0.0 launch. The state database format improve to twenty-eight.0.0 migrates in place, so no resync is required. You could find the discharge on GitHub, crates.io, and Docker Hub.

Thank You to Our Contributors

This launch was made potential by the work of @andres-pcg, @arya, @conradoplg, @dannywillems, @emersonian, @gustavovalverde, @nuttycom, @oxarbitrage, @syszery, @upbqdn, and @zmanian. Thanks on your continued contributions to Zebra.

Zebra is the Zcash Basis’s impartial, Rust-based implementation of the Zcash protocol. Study extra at github.com/ZcashFoundation/zebra.