CVE-2026-104422

Summary

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.

Affected Software

VendorProductVersion RangeStatus
ZcashFoundationzebra0 < 6.3.0affected
ZcashFoundationzebra6.3.0unaffected

Weaknesses

  • CWE-345: Insufficient Verification of Data Authenticity

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: yes
    • Technical Impact: partial

References