---
title: "CVE-2026-104430: Zebra zebrad & zebra-script - Denial of Service"
description: "Zebra zebrad 4.5.0 and zebra-script 7.0.0 contain a consensus divergence caused by incorrect counting of P2SH redeem script signature operations in legacy mode, letting remote attackers cause Zebra nodes to reject valid blocks, exploit requires broadcasting crafted P2SH spends."
url: https://panop.io/threat-heartbeat/CVE-2026-104430/
---

# CVE-2026-104430 Zebra zebrad & zebra-script - Denial of Service

Zebra zebrad 4.5.0 and zebra-script 7.0.0 contain a consensus divergence caused by incorrect counting of P2SH redeem script signature operations in legacy mode, letting remote attackers cause Zebra nodes to reject valid blocks, exploit requires broadcasting crafted P2SH spends.

CVSS base score 7.5 /10

High

CISA KEV

Not listed

Public exploit

None known

Authentication

Not required

EPSS

0.41% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-104430)

## Details

Type

Denial of Service

Impact

Denial Of Service

CVSS vector

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

Published

2 October 2026

Updated

15 October 2026

Weakness

[CWE-628](https://cwe.mitre.org/data/definitions/628.html)

## Vendor fix

Update to the latest version with accurate P2SH signature operation counting.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-104430](https://nvd.nist.gov/vuln/detail/CVE-2026-104430)
- [https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-2prc-cj5x-4443](https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-2prc-cj5x-4443)
- [https://www.vulncheck.com/advisories/zebra-4.5.0-consensus-split-via-p2sh-sigop-overcount](https://www.vulncheck.com/advisories/zebra-4.5.0-consensus-split-via-p2sh-sigop-overcount)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

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