CVE-2026-41583Network attack vector

Consensus split via incorrect sighash type handling

Published May 8, 2026 · Updated May 8, 2026

Consensus failure in Zcash Foundation Zebra before 4.3.1 allows remote attackers to split network consensus via invalid sighash types. The Rust caller introduced by an FFI refactor omits the V5 known-hash-type check and canonicalizes V4 hash types instead of preserving the raw byte. Submitting a V4 or V5 transaction with an invalid hash type makes affected Zebra nodes disagree with zcashd, partitioning the network and disrupting service.

CVSS severity9.3
Critical
EPSS probability0.28%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Consensus failure in Zcash Foundation Zebra before 4.3.1 allows remote attackers to split network consensus via invalid sighash types. The Rust caller introduced by an FFI refactor omits the V5 known-hash-type check and canonicalizes V4 hash types instead of preserving the raw byte. Submitting a V4 or V5 transaction with an invalid hash type makes affected Zebra nodes disagree with zcashd, partitioning the network and disrupting service.

The record

CVE
CVE-2026-41583
Published
May 8, 2026
Updated
May 8, 2026
Vendor
Zcash Foundation
Product
Zebra
Classifications
CWE-573, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 8, 2026CVE publishedPublication date reported by the CVE source.
  2. May 8, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=zebrad < 4.3.1
  2. Affected versionversion=zebra-script < 5.0.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Zcash Foundation · Zebraversion=zebrad < 4.3.1; version=zebra-script < 5.0.2

Published CVSS scores

9.1NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
9.3GitHub CNACVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:H/SA:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-573Improper Following of Specification by Caller
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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