CVE-2026-104427: Zcashfoundation Zebra

Medium severity, CVSS 5.9. EPSS: 0.3% chance of exploitation in the next 30 days.

Zebra before 6.1.0 contains an incomplete cleanup vulnerability in the state write task that allows remote unauthenticated peers to stall node synchronization by poisoning parent_error_map. Attackers can deliver a coinbase-malleated block sharing a canonical block's hash before it propagates, causing the next canonical block to be rejected and stalling the node for roughly 2,000 blocks.

Affected products

• Zcashfoundation Zebra: before 6.1.0 (fixed in 6.1.0)

Published 2026-10-02. Last modified 2026-10-05.