According to Foresight News, blockchain infrastructure company Espresso Systems tweeted an update that the Polygon zkEVM fork running on the Espresso Cortado testnet was restored last night and is available for use at any time. The team is still conducting further tests before asking Caldera to redeploy the Vienna OP chain, but the goal is to be back online tomorrow.

Foresight News reported yesterday that Espresso Systems tweeted that it had discovered and fixed some vulnerabilities in the Espresso Sequencer consensus that supports the Cortado testnet. The testnet has been closed while the fix is ​​being prepared and deployed. The above vulnerabilities are contained in the Espresso Sequencer and have nothing to do with Vienna deployed by Caldera OP Stack.