What’s Vulnerable › Vulnerabilities

CVE-2026-104419: Zebra before 6.3.0 Honest Peer Banning via Far-Ahead FindBlocks Hashes

• Severity: medium (CVSS 4.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.1% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-02 · updated 2026-10-05
• Weakness: CWE-345

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 products

• ZcashFoundation zebra: before 6.3.0 — fixed in 6.3.0

How to fix

Upgrade to a fixed version: ZcashFoundation zebra 6.3.0. Check the vendor advisory for mitigations.

References

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

Get alerted when CVE-2026-104419 or the next vulnerability affects your stack