What’s Vulnerable › Vulnerabilities

CVE-2026-104437: Zebra before 4.4.0 Consensus Split via SIGHASH_SINGLE Missing-Output Handling

• Severity: high (CVSS 7.4 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-02 · updated 2026-10-06
• Weakness: CWE-347

Description

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.

Affected products

• ZcashFoundation zebra: before 4.4.0 — fixed in 4.4.0

How to fix

Upgrade to a fixed version: ZcashFoundation zebra 4.4.0. Check the vendor advisory for mitigations.

References

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

Get alerted when CVE-2026-104437 or the next vulnerability affects your stack