---
id: CVE-2026-123558
title: >-
  Zebra before 7.0.0 Checkpoint Sync Denial of Service via Cancelled Verifier
  Rewind
summary: >-
  Zebra zebrad before 7.0.0 contains a denial of service vulnerability that
  allows a malicious peer to stall checkpoint sync by cancelling the verifier
  rewind after a failed commit. Attackers can serve a forged block with altered
  authorizi…
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-460
vendor: ZcashFoundation
product: zebra
affected:
  - zebra < 7.0.0
published: '2026-11-08'
updated: '2026-11-08'
sourceUpdated: '2026-11-08T01:37:59.650Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-123558'
references:
  - url: >-
      https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-2w9f-9wx8-f5c8
    label: GitHub Security Advisory (GHSA-2w9f-9wx8-f5c8)
  - url: >-
      https://www.vulncheck.com/advisories/zebra-before-7.0.0-checkpoint-sync-denial-of-service-via-cancelled-verifier-rewind
    label: >-
      VulnCheck Advisory: Zebra before 7.0.0 Checkpoint Sync Denial of Service
      via Cancelled Verifier Rewind
tags:
  - cve.org
ingestedAt: '2026-11-08T02:43:18.666Z'
---

## Overview

Zebra zebrad before 7.0.0 contains a denial of service vulnerability that allows a malicious peer to stall checkpoint sync by cancelling the verifier rewind after a failed commit. Attackers can serve a forged block with altered authorizing data plus a restart-triggering block, leaving the verifier rejecting honest blocks until restart.

## Affected

- `zebra < 7.0.0`

## Remediation

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