CVE-2026-104430
Published:October 02, 2026
Updated:October 09, 2026
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.
Affected Packages
https://github.com/ZcashFoundation/zebra.git (GITHUB):
Affected version(s) =v4.5.0 <v4.5.1Fix Suggestion:
Update to version v4.5.1zebrad (RUST):
Affected version(s) =4.5.0 <4.5.1Fix Suggestion:
Update to version 4.5.1zebra-script (RUST):
Affected version(s) =7.0.0 <7.0.1Fix Suggestion:
Update to version 7.0.1Related Resources (4)
Do you need more information?
Contact UsCVSS v4
Base Score:
8.7
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
NONE
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
7.5
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Weakness Type (CWE)
Function Call with Incorrectly Specified Arguments
EPSS
Base Score:
0.41