CVE-2026-104419

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

MEDIUM
4.8
CVSS Score
Published: October 2, 2026 at 11:38 AM UTC
Updated: October 5, 2026 at 04:17 PM UTC
2 products affected across 2 vendorsZebraZebra

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Severity
MEDIUM4.8
Exploit prediction
EPSS 0.1%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

95%
v < 6.3.0
Affected range stops below 6.3.0, so it looks safe — our inference, not a vendor statement
v < 6.3.0
Vendor states this is fixed in 6.3.0 (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

4.8MEDIUMVulnCheck
Attack Vector
NETWORK
Complexity
HIGH
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
LOW
Availability
LOW
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-345

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