---
id: CVE-2026-123560
title: Zebra before 7.0.0 Sync Denial of Service via Forged Checkpoint Block Body
summary: >-
  Zebra before 7.0.0 contains an incomplete cleanup vulnerability that allows
  unauthenticated peers to stall initial sync by serving a forged checkpoint
  block body. Attackers can supply a body with forged authorizing data near the
  final ch…
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-459
vendor: ZcashFoundation
product: zebra
affected:
  - zebra < 7.0.0
published: '2026-11-08'
updated: '2026-11-08'
sourceUpdated: '2026-11-08T01:38:01.040Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-123560'
references:
  - url: >-
      https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-9hq5-pfgc-cx5h
    label: GitHub Security Advisory (GHSA-9hq5-pfgc-cx5h)
  - url: >-
      https://www.vulncheck.com/advisories/zebra-before-7.0.0-sync-denial-of-service-via-forged-checkpoint-block-body
    label: >-
      VulnCheck Advisory: Zebra before 7.0.0 Sync Denial of Service via Forged
      Checkpoint Block Body
tags:
  - cve.org
ingestedAt: '2026-11-08T02:43:18.664Z'
---

## Overview

Zebra before 7.0.0 contains an incomplete cleanup vulnerability that allows unauthenticated peers to stall initial sync by serving a forged checkpoint block body. Attackers can supply a body with forged authorizing data near the final checkpoint, leaving rejected hashes in the sent-hash set so the node stops requesting blocks until restart.

## Affected

- `zebra < 7.0.0`

## Remediation

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