← Back
Summary
vulnerability in zfnd (CVE-2026-41583). Data can be tampered with by attackers. Exploitable via ``zcashd``.
AI summary openai / gpt-4o
A critical issue has been found in ZEBRA, a node software for the cryptocurrency Zcash. Systems running this software may experience conflicts between different nodes, leading potentially to network partitioning and loss of transaction integrity. The issue primarily involves differences in how transactions are verified, which could split the network. The solution is to update the software to its latest version to prevent such conflicts.
ZEBRA, a node implementation for Zcash, has been found to inadequately validate consensus rules. Specifically, the validation for sighash hash types in V5 transactions was missing, potentially causing consensus splits between Zebra and zcashd nodes, which could lead to network partitioning. Affected versions are prior to 4.3.1 for zebrad and 5.0.2 for zebra-script. To mitigate this vulnerability, it is essential to upgrade zebra to version 4.3.1 and zebra-script to version 5.0.2 or later.
❓ What is the problem
Consensus rule validation failure in Zcash node ZEBRA, specifically with sighash hash type for V5 transactions.
📍 Affected scope
In Zcash node software ZEBRA, prior to zebrad 4.3.1 and zebra-script 5.0.2.
🔥 Severity
Critical - potential for network partitioning and double-spend attacks due to consensus splits.
🔧 How to fix
Upgrade zebrad to version 4.3.1 and zebra-script to version 5.0.2.
🛡️ Workaround
No workaround available.
🔍 Detection
Monitor for consensus splits between Zebra and zcashd nodes in the network.
Related past incidents Similar incidents extracted from past CVEs
A consensus failure vulnerability in Bitcoin that caused a network split due to consensus differences in transaction validation.
A vulnerability in Ethereum's Geth client leading to a consensus split due to differences in transaction processing.
A critical vulnerability in Bitcoin leading to consensus failure and the potential for double-spending.
If this happens at your company Expected impact per business scenario
📌 Cryptocurrency exchanges using ZEBRA nodes.
A consensus split could cause transaction verification issues, leading to potential financial discrepancies.
📌 Decentralized finance platforms utilizing Zcash with ZEBRA nodes.
Disruptions and inconsistencies in transaction processing could occur, impacting smart contract operations.
📌 Cryptocurrency mining operations relying on ZEBRA nodes.
Miners may unknowingly process invalid transactions, leading to financial loss and network instability.
Recommended action
Companies should immediately update their ZEBRA software to the latest secure version to maintain transaction integrity and network stability.
Response Actions (7 steps)
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'zfnd' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で `zfnd` を grep し、稼働しているサービス・バージョンを把握する。
-
2Match against affected range verify
Confirm if version satisfies `<4.3.1`Step 1 で見つかったバージョンが影響範囲 `<4.3.1` に該当するか照合。本番で稼働中ならインシデント扱い。
-
7Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番では Step 3 と同じログクエリでアラート再発が無いか継続監視。
References
- patch [email protected]