Network Upgrade 6.2 The mainnet activation of the immediate NU6.2 network upgrade is supported by the 6.20.0 release, with an activation height of 3364600, which should occur at approximately 03:00 UTC, June 3, 2026. Please upgrade to this release, or any subsequent release, in order to follow the NU6.2 network upgrade. Security fix: remediation of the Orchard circuit The Zcash Open Development…
Notable changes Security Fixes This release addresses several consensus and denial-of-service vulnerabilities in zcashd , all reachable by a remote peer or miner. This is a time-critical upgrade. It is released in coordination with a soft fork that activates at mainnet block height 3363426 (approximately 02:00 UTC on 2026-06-02). Mining nodes that have not upgraded before activation are likely to…
Notable changes Security Fixes This release addresses CVE-2024-52911 , a critical use-after-free vulnerability in zcashd 's block validation. Any inbound peer can trigger the bug by sending a crafted invalid block, causing the receiving node to access freed memory during script verification. The most likely impact is a single-node crash; the bug is reachable on every multi-core node running with…
Notable changes Security Fixes This release addresses several security vulnerabilities that could have caused nodes to diverge from consensus with Zebra. These vulnerabilities were reported privately by white-hat security researchers and handled through coordinated disclosure by Shielded Labs, Zcash Open Development Lab (ZODL), and Zcash Foundation engineers, in coordination with mining pools. The…
Notable changes Security Fixes This release addresses several security vulnerabilities that could have caused nodes to crash or diverge from consensus with Zebra, or that could have disabled the defence-in-depth provided by pool turnstile checks. These vulnerabilities were reported privately by white-hat security researcher Alex “Scalar” Sol and handled through coordinated disclosure by Shielded…
Notable changes Fix to Sprout transaction verification logic A vulnerability was identified in zcashd that could have allowed invalid transactions to be accepted under certain conditions, which potentially could have resulted in the draining of user funds from the old, deprecated Sprout pool. The patch fixing this bug, corresponding to db969c6 , has been deployed by mining pools that comprise a…
Notable changes This release makes no changes to zcashd behavior; it has no effect other than to set a new end-of-service halt height.
Notable changes Network Upgrade 6.1 The mainnet activation of the NU6.1 network upgrade is supported by the 6.10.0 release, with an activation height of 3146400, which should occur on approximately November 23, 2025. Please upgrade to this release, or any subsequent release, in order to follow the NU6.1 network upgrade. The following ZIPs are being deployed as part of this upgrade: ZIP 271:…
Notable changes Network Upgrade 6.1 The code preparations for the Network Upgrade 6.1 consensus rules are finished and included in this release. The following ZIPs are being deployed: ZIP 271: Deferred Dev Fund Lockbox Disbursement ZIP 1016: Community and Coinholder Funding Model (partially) NU6.1 will activate on testnet at height 3,536,500 , and can also be activated at a specific height in…
zcashd release candidate v6.3.0-rc1