CVE-2026-104419

MEDIUM 4.8

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

CVSS Score

4.8

EPSS Score

0.0%

EPSS Percentile

0th

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.

CWE	CWE-345
Vendor	zcashfoundation
Product	zebra
Published	Oct 2, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L

Attack Vector

Network

Attack Complexity

High

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

Low

Availability

Low

Affected Versions

ZcashFoundation / zebra

0 < 6.3.0

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-qhr3-cvch-5fh2 vulncheck.com: https://www.vulncheck.com/advisories/zebra-before-6.3.0-honest-peer-banning-via-far-ahead-findblocks-hashes

Credits

🔍 zakura-security