Zebra zebrad 4.5.0 and zebra-script 7.0.0 count P2SH redeem script signature operations in legacy mode rather than zcashd's accurate P2SH mode, overcounting CHECKMULTISIG preceded by OP_1 through OP_16 as 20 sigops and causing a consensus divergence. Remote attackers can broadcast P2SH spends using low-threshold multisig redeem scripts so that a block zcashd accepts exceeds Zebra's inflated MAX_BLOCK_SIGOPS count, causing Zebra nodes to reject it and stall off the chain.

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Fixes

Solution

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Workaround

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History

Fri, 02 Oct 2026 13:30:00 +0000

Type Values Removed Values Added
First Time appeared Zcashfoundation
Zcashfoundation zebra
Vendors & Products Zcashfoundation
Zcashfoundation zebra

Fri, 02 Oct 2026 11:45:00 +0000

Type Values Removed Values Added
Description Zebra zebrad 4.5.0 and zebra-script 7.0.0 count P2SH redeem script signature operations in legacy mode rather than zcashd's accurate P2SH mode, overcounting CHECKMULTISIG preceded by OP_1 through OP_16 as 20 sigops and causing a consensus divergence. Remote attackers can broadcast P2SH spends using low-threshold multisig redeem scripts so that a block zcashd accepts exceeds Zebra's inflated MAX_BLOCK_SIGOPS count, causing Zebra nodes to reject it and stall off the chain.
Title Zebra 4.5.0 Consensus Split via P2SH Sigop Overcount
First Time appeared Zfnd
Zfnd zebra
Weaknesses CWE-628
CPEs cpe:2.3:a:zfnd:zebra:*:*:*:*:*:*:*:*
Vendors & Products Zfnd
Zfnd zebra
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

cvssV4_0

{'score': 8.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-10-02T15:17:44.203Z

Reserved: 2026-10-02T00:50:26.603Z

Link: CVE-2026-104430

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-02T12:17:13.467

Modified: 2026-10-02T12:17:13.467

Link: CVE-2026-104430

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-10-02T13:15:15Z

Weaknesses