Medium severity · published Oct 2, 2026
CVE-2026-104419
Zebra before 6.3.0 Honest Peer Banning via Far-Ahead FindBlocks Hashes
4.8
CVSS
0.1%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Confidentiality
None
Integrity
Low
Availability
Low
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.1% · higher than 2% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
ZE
zebra · ZcashFoundation
before 6.3.0 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-104419
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-104419
vendor-advisory
https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-qhr3-cvch-5fh2
third-party-advisory
https://www.vulncheck.com/advisories/zebra-before-6.3.0-honest-peer-banning-via-far-ahead-findblocks-hashes
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