Low severity · published Oct 2, 2026
CVE-2026-104424
Zebra before 6.1.0 Incorrect Block Size Calculation in getblocktemplate
3.7
CVSS
0.3%
EPSS
No
On KEV
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 vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
Low
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 20% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
ZE
zebra · ZcashFoundation
before 6.1.0 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-104424
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-104424
vendor-advisory
https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-95m2-vx53-v2jw
third-party-advisory
https://www.vulncheck.com/advisories/zebra-before-6.1.0-incorrect-block-size-calculation-in-getblocktemplate
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