CVE-2026-104437

HIGH 7.4

Zebra before 4.4.0 Consensus Split via SIGHASH_SINGLE Missing-Output Handling

CVSS Score

7.4

EPSS Score

0.0%

EPSS Percentile

0th

Zebra before 4.4.0 contains a consensus divergence vulnerability in V5 transparent signature verification, computing a ZIP-244 digest for SIGHASH_SINGLE inputs lacking corresponding outputs instead of failing. Attackers can craft V5 transactions with fewer outputs than inputs that Zebra accepts and templates via getblocktemplate, producing blocks zcashd rejects.

CWE	CWE-347
Vendor	zcashfoundation
Product	zebra
Published	Oct 2, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H

Attack Vector

Network

Attack Complexity

High

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

High

Availability

High

Affected Versions

ZcashFoundation / zebra

0 < 4.4.0

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-cwfq-rfcr-8hmp vulncheck.com: https://www.vulncheck.com/advisories/zebra-before-4.4.0-consensus-split-via-sighash-single-missing-output-handling

Credits

🔍 sangsoo-osec 🔍 defuse mpguerra upbqdn