Zcash completes network upgrade after block explorer issues

June 04, 2026

Zcash activated a major network upgrade on June 3 that briefly caused block explorers to show no new blocks. Developers also suspended Orchard transactions to fix a privacy pool bug.

The Zcash blockchain upgrade took place at block 3,364,600. Many block explorers failed to update their nodes immediately, creating the appearance that no new blocks were produced for more than four hours after 5:27 AM UTC. Josh Swihart, CEO of ZODL, said the issue stemmed from explorers still watching the old chain while miners moved to the upgraded version. Mert Mumtaz of Helius confirmed the same explanation. Separately, Zcash developers paused Orchard transactions to address a vulnerability that could have allowed double-spending in the privacy pool. No exploitation occurred. ZEC rose 8 percent over the past week and 46 percent over the past month.

人们在说什么

Users and developers on X discussed Zcash's June 3 network upgrade to patch an Orchard pool vulnerability, clarifying that block explorers lagged due to node updates while the chain continued operating. Sentiments included relief over the swift fix with no exploitation, neutral explanations of events, and some skepticism about privacy protocol complexities and potential risks.

INTEL: Zcash coordinated a network upgrade due to an Orchard pool soundness vulnerability.

Multiple block explorers, including the official explorer, still appear to be catching up after the upgrade, while block production is reportedly continuing, as seen on ZecMiningPool.

We… https://t.co/743lwfwqJ7 pic.twitter.com/eW3tJNz6Tf

— Solid Intel 📡 (@solidintel_x) 2026年6月3日

Apparent Zcash outage was a block explorer problem.

"A coordinated Zcash network upgrade was activated at block 336400. Many block explorers had not yet updated their nodes at the time of the upgrade, resulting in a loss of visibility into the chain's state," CEO of ZODL Josh…

— Zcash Open Development Lab (@zodl_co) 2026年6月3日

Zcash emergency upgrade for an Orchard bug is a reminder that privacy protocols carry complexity cost in places consensus audits do not usually look. The shielded pool adds a new failure mode, the emergency coordination path becomes load-bearing, and 'no evidence of exploit'…

— ZeroDayDev (@ZeroDayDevApp) 2026年6月3日

The network was not down.

Block explorers failed to update following a coordinated soft fork, creating the appearance of an outage.

What actually happened: Zcash executed an emergency protocol upgrade after discovering a soundness flaw in the Orchard shielded pool's Halo 2…

— ΦPhiMandelbrØτ (@PhiMandelbr0t) 2026年6月3日

Orchard working as expected now

— Eric Kuhn (@erickuhn19) 2026年6月4日

来源

• https://decrypt.co/369896/zcash-completes-most-ambitious-network-upgrade-zec-resumes-recent-surge
• https://cointelegraph.com/news/zcash-orchard-vulnerability-emergency-upgrade
• https://www.coindesk.com/tech/2026/06/03/privacy-focused-zcash-blockchain-has-not-produced-a-block-for-four-hours