---
id: CVE-2026-104429
title: >-
  Zebra (zebrad) 5.0.0 before 6.0.0-rc.0 does not apply its per-peer mempool
  admission cap to transactions received as direct P2P tx messages, because
  these are queued without the sending peer recorded as their source
summary: >-
  Zebra (zebrad) 5.0.0 before 6.0.0-rc.0 does not apply its per-peer mempool
  admission cap to transactions received as direct P2P tx messages, because
  these are queued without the sending peer recorded as their source. A remote
  inbound pee…
severity: medium
cvss: 5.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'
cwe:
  - CWE-770
vendor: ZcashFoundation
product: zebra
affected:
  - zebra < 6.0.0-rc.0
published: '2026-10-02'
updated: '2026-10-02'
sourceUpdated: '2026-10-02T13:17:43.500'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-104429'
references:
  - url: >-
      https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-m9xx-8rcj-vmgp
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/zebra-before-6.0.0-rc.0-per-peer-mempool-admission-bypass-via-p2p-tx-messages
    label: disclosure@vulncheck.com
tags:
  - nvd
  - cve.org
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-10-02T12:27:13.306414Z'
ingestedAt: '2026-10-02T12:17:44.332Z'
---

## Overview

Zebra (zebrad) 5.0.0 before 6.0.0-rc.0 does not apply its per-peer mempool admission cap to transactions received as direct P2P tx messages, because these are queued without the sending peer recorded as their source. A remote inbound peer can push many unique transactions to occupy a disproportionate share of mempool admission slots, crowding out honest peers' transaction relay.

## Remediation

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