CVE-2026-104430

Zebra 4.5.0 Consensus Split via P2SH Sigop Overcount

HIGH
7.5
CVSS Score
Published: October 2, 2026 at 11:38 AM UTC
Updated: October 2, 2026 at 05:59 PM UTC
2 products affected across 2 vendorsZebraZebra

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Severity
HIGH7.5
Exploit prediction
EPSS 0.4%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

95%
4.5.0 ≤ v < 4.5.17.0.0 ≤ v < 7.0.1
Affected range stops below 4.5.1, so it looks safe — our inference, not a vendor statement
Affected range stops below 7.0.1, so it looks safe — our inference, not a vendor statement
4.5.0 ≤ v < 4.5.17.0.0 ≤ v < 7.0.14.5.07.0.0
Vendor states this is fixed in 4.5.1 (unaffected)
Vendor states this is fixed in 7.0.1 (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGHVulnCheck
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-628

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