CVE-2026-52735

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, p2sh_input_sigop_count used the pure-Rust script::Code::sig_op_count path, whose try_fold parser stops at disabled opcodes such as OP_CODESEPARATOR and returns only the partial count accumulated before the error. The zcashd reference implementation continues static signature-operation counting through disabled opcodes, so an attacker can broadcast P2SH spends that Zebra counts below MAX_BLOCK_SIGOPS while zcashd counts above the 20,000-operation limit. If a Zebra miner includes those transactions, Zebra validators accept the block while zcashd validators reject it, creating a consensus chain split that affects network integrity and availability without requiring the attacker to produce a block. This issue is fixed in version 4.5.0.

• CWE-684

• https://github.com/ZcashFoundation/zebra/commit/1440b43ca7df59aca948090d45117557b217a6cd
• https://github.com/ZcashFoundation/zebra/releases/tag/v4.5.0
• https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-gf9r-m956-97qx

Published

Aug 18, 2026

Last Modified

Sep 9, 2026

Status

Deferred

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
• Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
• PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
• AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.

• CVE-2026-5273Use after free in CSS in Google Chrome prior to 146.0.7680.1…6.3
• CVE-2026-52730Xibo is an open source digital signage platform with a web c…4.3
• CVE-2026-52731ZEBRA is a Zcash node written entirely in Rust. Prior to 4.5…6.5
• CVE-2026-52732ZEBRA is a Zcash node written entirely in Rust. Prior to 4.5…5.3
• CVE-2026-52733ZEBRA is a Zcash node written entirely in Rust. Prior to 4.5…6.5
• CVE-2026-52734ZEBRA is a Zcash node written entirely in Rust. Prior to 4.5…5.3
• CVE-2026-52736ZEBRA is a Zcash node written entirely in Rust. Prior to 4.5…8.7
• CVE-2026-52737ZEBRA is a Zcash node written entirely in Rust. Prior to 4.5…5.3
• CVE-2026-52738ZEBRA is a Zcash node written entirely in Rust. Prior to 4.5…6.9
• CVE-2026-52739ZEBRA is a Zcash node written entirely in Rust. Prior to 4.5…5.9
• CVE-2026-5274Integer overflow in Codecs in Google Chrome prior to 146.0.7…8.8
• CVE-2026-52740GoCD is a continuous deliver server. From 18.7.0 until 26.1.…5.3