---
id: CVE-2026-123554
title: >-
  Zebra zebrad 6.4.0 before 7.0.0 Denial of Service via Mempool
  Coinbase-Maturity Check
summary: >-
  Zebra zebrad 6.4.0 before 7.0.0 performs quadratic work in the mempool
  coinbase-maturity check because Transaction::coinbase_spend_restriction()
  rebuilds the transaction's output list once per spent outpoint. Any connected
  peer can repea…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cvssSource: cna
cwe:
  - CWE-407
vendor: ZcashFoundation
product: zebra
affected:
  - zebra >= 6.4.0 < 7.0.0
published: '2026-11-08'
updated: '2026-11-08'
sourceUpdated: '2026-11-08T01:37:56.894Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-123554'
references:
  - url: >-
      https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-7jp4-mq53-4cvq
    label: GitHub Security Advisory (GHSA-7jp4-mq53-4cvq)
  - url: >-
      https://github.com/ZcashFoundation/zebra/commit/08743d669b33a19bce2a5d54001bd468c03a196e
    label: Patch Commit
  - url: >-
      https://www.vulncheck.com/advisories/zebra-zebrad-6.4.0-before-7.0.0-denial-of-service-via-mempool-coinbase-maturity-check
    label: >-
      VulnCheck Advisory: Zebra zebrad 6.4.0 before 7.0.0 Denial of Service via
      Mempool Coinbase-Maturity Check
tags:
  - cve.org
ingestedAt: '2026-11-08T02:43:18.668Z'
---

## Overview

Zebra zebrad 6.4.0 before 7.0.0 performs quadratic work in the mempool coinbase-maturity check because Transaction::coinbase_spend_restriction() rebuilds the transaction's output list once per spent outpoint. Any connected peer can repeatedly send unsigned transactions with many transparent inputs and outputs, which are rejected without a misbehavior score, to pin verification threads.

## Affected

- `zebra >= 6.4.0 < 7.0.0`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.