Vulnerability · Published Oct 2, 2026 · Assigned by VulnCheck

CVE-2026-104430Zebra 4.5.0 Consensus Split via P2SH Sigop Overcount

High 7.5

In plain English

A high-severity security flaw in zebra from ZcashFoundation. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 35% of all known vulnerabilities).

Severity (CVSS 3.1)7.5High

Exploit odds (30 days)0.4%top 64.6% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official 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 products (as reported)

Vendor	Product	Versions
ZcashFoundation	zebra	4.5.0 – before 4.5.1
ZcashFoundation	zebra	7.0.0 – before 7.0.1

Weakness: CWE-628 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References

GitHub Security Advisory (GHSA-2prc-cj5x-4443) vendor-advisory
VulnCheck Advisory: Zebra 4.5.0 Consensus Split via P2SH Sigop Overcount third-party-advisory