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TI-2026-66062 Aliases CVE-2026-104419GHSA-rrh7-6j2w-crgw

Zebra before 6.3.0 Honest Peer Banning via Far-Ahead FindBlocks Hashes

Priority LOW 27CWE-345Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
High
Attack requirements
Present
Impact type
Security bypass
Confidentiality · integrity · availability
None · Low · Low
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-345.

Summary

Zebra (zebrad) 4.5.0 before 6.3.0 discards which peer supplied the block hashes in FindBlocks responses, then assigns 100 misbehavior points, the ban threshold, to whichever peer serves a requested block more than 50,000 heights above the tip. A remote peer can return real far-ahead hashes to a syncing node so that honest peers get banned, eroding its peer set and raising eclipse risk.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00126 2nd percentileScored 2026-11-07
Fix Fixed zebra (ZcashFoundation): 6.3.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
ZcashFoundationzebrabefore 6.3.06.3.0Patch availableCNA
  • zebra VendorZcashFoundation Affected before 6.3.0 Fixed in 6.3.0 Patch available CNA

Remediation

  • Fix · CNA zebra (ZcashFoundation) Fixed in 6.3.0

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    ZcashFoundation zebra 6.3.0

    4 records Highest priority Priority MEDIUM 1 MEDIUM, 3 LOW

    Other records, highest priority first

    • TI-2026-66065 Zebra before 6.3.0 Block Sync Denial of Service via Coinbase scriptSig RewritePriority MEDIUM 43
    • TI-2026-66075 Zebra before 6.3.0 False Readiness via Discarded One-Hash FindBlocks ResponsePriority LOW 36
    • TI-2026-66063 Zebra before 6.3.0 Peer Misbehavior Ban Bypass via Gossiped BlocksPriority LOW 36
    Show all 4 records →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-104419
  2. 2026-10-03 Alias added: GHSA-rrh7-6j2w-crgw
  3. 2026-10-04 Priority changed: MEDIUM → LOW
  4. 2026-10-05 CISA SSVC decision points changed

References

Advisory 1

  • TI-2026-66079 Zebra before 4.4.0 Consensus Split via SIGHASH_SINGLE Missing-Output Handling CVSS 4.0HIGH 8.3
  • TI-2026-37850 ZEBRA: Mempool transaction admission denial via single-peer inbound queue saturation CVSS 3.1MEDIUM 5.3
  • TI-2026-71182 Improper block validation in Zebra gossip lets peers drop new blocks CVSS 4.0MEDIUM 6.3
  • TI-2026-29537 Zebra: addr/addrv2 Deserialization Resource Exhaustion CVSS 4.0MEDIUM 6.3
  • TI-2026-86702 Incomplete cleanup in Zebra lets peers stall initial sync CVSS 4.0HIGH 8.7
  • TI-2026-86701 Quadratic signature hashing in Zcash Zebra enables denial of service CVSS 4.0HIGH 8.7
See all 51 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences