Zcash Foundation: Zebra 4.4.0 Released—Multiple Consensus-Level Security Vulnerabilities Fixed; Nodes Urged to Upgrade Immediately
The Zcash Foundation officially announced the release of Zebra 4.4.0, which addresses multiple critical consensus-level security vulnerabilities. All node operators are strongly advised to upgrade immediately. The vulnerabilities include a denial-of-service (DoS) flaw that could permanently halt the discovery of new blocks; a signature operation (sigop) counting error in block validation that may cause consensus divergence; abnormal handling of transparent transaction signature hashes; and a memory allocation amplification attack risk.
The Zcash Foundation stated that some of these vulnerabilities could cause Zebra nodes to accept blocks rejected by zcashd, potentially triggering a chain fork. Without timely upgrades, nodes risk interruption of block discovery, consensus forks, and amplified resource consumption. No alternative mitigations are currently available.