CVE-2026-104422
The block sync download path in Zebra (zebrad) before 6.3.0 reads a block's height from its unvalidated coinbase scriptSig and drops blocks that appear too far behind the tip before consensus validation, without penalizing the supplying peer. Because V5 transaction IDs exclude the scriptSig, a malicious peer can repeatedly serve a canonical block whose coinbase claims height 1 while keeping the requested hash, delaying the node's discovery of the newest block.
Published:Oct 2, 2026
Last Modified:Oct 2, 2026
EPS:Oct 2, 2026
EPSS Score:
CVSS Score:7.5
Affected Products
Vendor
Product
Action
Vendor
Zcashfoundation
Product
Zebra
Zcashfoundation
Zebra
Vendor
Zfnd
Product
Zebra
Zfnd
Zebra
Exploits
No exploit reference
Common Weakness Enumeration
Common Attack Pattern Enumeration and Classification (CAPEC)
Related CVEs
Common Vulnerability Scoring System
Attack Vector
Network
Adjacent
Local
Physical
Privileges Required
None
Low
High
User Interaction
None
Required
Scope
Unchanged
Changed
Confidentiality
None
Low
High
Integrity
None
Low
High
Availability
None
Low
High
