CVE-2026-104427

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.

• https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-8gxx-hc65-vv82
• https://www.vulncheck.com/advisories/zebra-before-6.1.0-chain-stall-via-stale-parent-error-map-entry