CVE-2026-104424: Incorrect Calculation of Buffer Size in ZcashFoundation zebra
Zebra before 6.1.0 contains an incorrect calculation vulnerability in its ZIP-317 block template selector that omits header and transaction-count size from the block budget. Attackers can place valid selectable transactions in a victim miner's mempool to shape templates into oversized blocks, causing rejection and wasted proof-of-work.
AI Analysis
Technical Summary
CVE-2026-104424 describes an incorrect calculation vulnerability in ZcashFoundation's zebra software prior to version 6.1.0. The ZIP-317 block template selector fails to account for the header and transaction-count sizes when calculating the block budget. Attackers can exploit this by placing valid selectable transactions in a victim miner's mempool, causing the miner to produce oversized block templates that are rejected by the network, resulting in wasted computational effort.
Potential Impact
The vulnerability can lead to the creation of oversized block templates that are rejected by the network, causing miners to waste proof-of-work. This can reduce mining efficiency and potentially disrupt normal mining operations. There is no indication of remote code execution or data compromise.
Mitigation Recommendations
Upgrade zebra to version 6.1.0 or later where this vulnerability is fixed. No other mitigation is indicated.
CVE-2026-104424: Incorrect Calculation of Buffer Size in ZcashFoundation zebra
Description
Zebra before 6.1.0 contains an incorrect calculation vulnerability in its ZIP-317 block template selector that omits header and transaction-count size from the block budget. Attackers can place valid selectable transactions in a victim miner's mempool to shape templates into oversized blocks, causing rejection and wasted proof-of-work.
CVSS v4.0
Score 6.3medium
Affected software
ZcashFoundation
zebra
pkg:github/zcashfoundation/zebraRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-104424 describes an incorrect calculation vulnerability in ZcashFoundation's zebra software prior to version 6.1.0. The ZIP-317 block template selector fails to account for the header and transaction-count sizes when calculating the block budget. Attackers can exploit this by placing valid selectable transactions in a victim miner's mempool, causing the miner to produce oversized block templates that are rejected by the network, resulting in wasted computational effort.
Potential Impact
The vulnerability can lead to the creation of oversized block templates that are rejected by the network, causing miners to waste proof-of-work. This can reduce mining efficiency and potentially disrupt normal mining operations. There is no indication of remote code execution or data compromise.
Mitigation Recommendations
Upgrade zebra to version 6.1.0 or later where this vulnerability is fixed. No other mitigation is indicated.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- VulnCheck
- Date Reserved
- 2026-10-02T00:46:23.830Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6abf99afa43b0b3b89b26903
Added to database: 10/02/2026, 11:46:55 UTC
Last enriched: 10/02/2026, 12:02:45 UTC
Last updated: 10/03/2026, 03:09:11 UTC
Views: 12
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