All vulnerabilities
CVE-2026-104430GHSA-2prc-cj5x-4443

Zebra 4.5.0 Consensus Split via P2SH Sigop Overcount

ZcashFoundation zebra
Open in ThreatlineRecord JSON
CVSS
8.7High
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.41%Chance of exploitation activity in the next 30 days, higher than 34% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed in4.5.1Also 7.0.1CVE List
Published2 Oct 2026Updated 2 Oct 2026CVE List

What fixes it

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

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.

Text from CVE List

Affected versions 4

  • zebraaffected: 4.5.0 before 4.5.1CVE List
  • zebraunaffected: 4.5.1CVE List
  • zebraaffected: 7.0.0 before 7.0.1CVE List
  • zebraunaffected: 7.0.1CVE List

References 2