CVE-2026-52735 ZEBRA: Consensus divergence via P2SH sigop undercount in pure-Rust disabled-opcode parser

ZEBRA is a Zcash node written entirely in Rust. Prior to 4.5.0, Zebra can accept a block that zcashd rejects because the P2SH signature-operation counter undercounts redeem scripts containing a disabled opcode followed by signature opcodes. In zebra-script/src/lib.rs, p2shinputsigopcount used the...

CVE-2026-52735

Zebra (a Rust-based Zcash node) used a pure-Rust P2SH sigop counter that short-circuited on disabled opcodes like OP_CODESEPARATOR, undercounting sigops compared to zcashd. An attacker without mining power could trigger a chain split by broadcasting P2SH spends with malicious redeem scripts. Fixe...

GHSA-GF9R-M956-97QX zebrad has consensus divergence via P2SH sigop undercount in pure-Rust disabled-opcode parser

Am I affected You are affected if: 1. You run any version of zebrad up to and including v4.4.1. 2. Your node validates blocks on mainnet, testnet, or any network where both Zebra and zcashd nodes participate. All default configurations are affected. No feature flags, non-default settings, or...