---
id: CVE-2026-104428
title: >-
  The getblock RPC method in zebra-rpc before 11.0.0, used by the Zcash
  Foundation's Zebra node, panics on verbosity 2 for a side-chain block because
  the block's -1 confirmations sentinel is converted to u32 with .expect(),
  aborting the pr…
summary: >-
  The getblock RPC method in zebra-rpc before 11.0.0, used by the Zcash
  Foundation's Zebra node, panics on verbosity 2 for a side-chain block because
  the block's -1 confirmations sentinel is converted to u32 with .expect(),
  aborting the pr…
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-617
vendor: ZcashFoundation
product: zebra
affected:
  - zebra < 11.0.0
published: '2026-10-02'
updated: '2026-10-02'
sourceUpdated: '2026-10-02T12:17:13.177'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-104428'
references:
  - url: >-
      https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-x6v8-c2xp-928m
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/zebra-before-11.0.0-denial-of-service-via-getblock-verbosity-2
    label: disclosure@vulncheck.com
tags:
  - nvd
  - cve.org
ingestedAt: '2026-10-02T12:17:44.332Z'
---

## Overview

The getblock RPC method in zebra-rpc before 11.0.0, used by the Zcash Foundation's Zebra node, panics on verbosity 2 for a side-chain block because the block's -1 confirmations sentinel is converted to u32 with .expect(), aborting the process. Remote unauthenticated attackers, directly or through lightwalletd, can repeat this call to keep the node in a crash loop.

## Remediation

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