After discovering a vulnerability in the Orchard shielding pool, Zcash coordinated with validators to implement an emergency protocol upgrade. The project team stated that the issue was discovered during routine audits and security checks, and there are currently no known instances of exploitation; user funds and privacy have not been affected.
Orchard trading is temporarily suspended.
This adjustment took effect at approximately 10:30 PM Eastern Time on June 1st. During the upgrade, wallet users will be temporarily unable to send or receive Orchard funds until the issue is resolved.
However, the Zcash network has not completely shut down. The project team stated that earlier Sapling shielded pools, transparent addresses, and ZEC balances held on exchanges remain operational. The team anticipates that Orchard trading will resume later on June 2nd.
Fixes involving consensus layer changes
The developers have not yet disclosed the technical details of the vulnerability, but have made it clear that this is not a regular software update, but rather requires modifying the rules at the protocol layer. This means that validators will need to adopt new consensus rules to complete the fix.
Therefore, this action has been described by some observers as an emergency intervention "similar to a hard fork." However, this is not a controversial fork that will create a new chain. The current Zcash ecosystem is basically progressing along the same upgrade path, with the goal of completing the repairs without affecting the overall network operation as much as possible.
Other deployment parties received the notification simultaneously.
The project team also stated that they are notifying other protocol maintainers who have deployed Orchard. Because the upgrade is still ongoing, the development team has not yet disclosed full technical information; this practice is typically to reduce the risk of exploitation before patches are widely deployed.
Based on currently available information, Zcash's approach is to temporarily isolate the affected Orchard subsystem, rather than suspending the entire network. For users, the short-term impact is mainly concentrated on Orchard-related transfer functions; most other on-chain activities will continue.
