The Zcash Foundation released Zebra 4.5.1 as an emergency security update to address a consensus-critical flaw involving incorrect sigop counting in Pay-to-Script-Hash (P2SH) transactions. According to the source, the bug could have created consensus fork risk by causing nodes to disagree on transaction validity. The release also fixes an incomplete patch included in Zebra 4.5.0, which had been published the previous day. The new report adds that Zcash was trading around $572.12 following the rushed release.