CVE-2026-104437

Zebra before 4.4.0 Consensus Split via SIGHASH_SINGLE Missing-Output Handling

HIGH
7.4
CVSS Score
Published: October 2, 2026 at 11:38 AM UTC
Updated: October 6, 2026 at 03:17 AM UTC
2 products affected across 2 vendorsZebraZebra

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Severity
HIGH7.4
Exploit prediction
EPSS 0.2%
SSVC
PoC

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

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

95%
v < 4.4.0
Affected range stops below 4.4.0, so it looks safe — our inference, not a vendor statement
v < 4.4.0
Vendor states this is fixed in 4.4.0 (unaffected)

Remediation

No guide yet

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

SSVC — Action Prioritization

SSVCPoCNot automatableTotal impact

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

CVSS

7.4HIGHVulnCheck
Attack Vector
NETWORK
Complexity
HIGH
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-347

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