---
id: CVE-2026-52739
title: ZEBRA is a Zcash node written entirely in Rust
summary: >-
  ZEBRA is a Zcash node written entirely in Rust. Prior to 4.5.0, a malicious
  block producer can terminate zebrad by placing the same shielded transaction
  in a non-finalized parent block and its child. In
  zebra-state/src/service/non_finali…
severity: medium
cvss: 5.9
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-248
vendor: zebra-state
product: zebra-state
affected:
  - zebra-state <= 6.0.0
  - zebrad <= 4.4.1
patched:
  - zebra-state 7.0.0
  - zebrad 4.5.0
published: '2026-08-18'
updated: '2026-09-09'
sourceUpdated: '2026-09-09T21:13:25.910'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-52739'
references:
  - url: >-
      https://github.com/ZcashFoundation/zebra/commit/1440b43ca7df59aca948090d45117557b217a6cd
    label: security-advisories@github.com
  - url: 'https://github.com/ZcashFoundation/zebra/releases/tag/v4.5.0'
    label: security-advisories@github.com
  - url: >-
      https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-hhm7-qrv5-h4r6
    label: security-advisories@github.com
  - url: >-
      https://github.com/ZcashFoundation/zebra/blob/d4cd662c716382f6397d2a730148025a1ca79fec/Cargo.toml#L304-L305
  - url: >-
      https://github.com/ZcashFoundation/zebra/blob/d4cd662c716382f6397d2a730148025a1ca79fec/zebra-consensus/src/transaction.rs#L521-L526
  - url: >-
      https://github.com/ZcashFoundation/zebra/blob/d4cd662c716382f6397d2a730148025a1ca79fec/zebra-state/src/service/non_finalized_state/chain.rs#L1608-L1628
  - url: 'https://github.com/advisories/GHSA-hhm7-qrv5-h4r6'
tags:
  - nvd
  - ghsa
  - rust
epss: 0.00515
epssPercentile: 0.41429
ecosystem: rust
ingestedAt: '2026-07-02T20:42:45.864Z'
---

## Overview

ZEBRA is a Zcash node written entirely in Rust. Prior to 4.5.0, a malicious block producer can terminate zebrad by placing the same shielded transaction in a non-finalized parent block and its child. In zebra-state/src/service/non_finalized_state/chain.rs, Chain::push originally inserted the transaction hash into tx_loc_by_hash and asserted uniqueness before updating shielded data and running the duplicate Sprout, Sapling, or Orchard nullifier checks. The repeated transaction therefore reached the transactions must be unique within a single chain assertion before contextual validation could reject it cleanly. Zebra release builds use panic equals abort, so the reachable assertion terminates the entire process; exploitation requires either two consecutive attacker-mined blocks or an attacker-mined child immediately after an honest block includes the attacker's shielded transaction. This issue is fixed in version 4.5.0.

## Remediation

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

## Package advisory (CVE-2026-52739)

Affected packages:

- `zebra-state <= 6.0.0`
- `zebrad <= 4.4.1`

Patched in:

- `zebra-state 7.0.0`
- `zebrad 4.5.0`

Source: https://github.com/advisories/GHSA-hhm7-qrv5-h4r6