CVE-2026-104436: Zcashfoundation Zebra

Low severity, CVSS 3.7. EPSS: 0.3% chance of exploitation in the next 30 days.

Zebra before 4.5.0 contains an uncontrolled resource consumption vulnerability that allows remote P2P peers to exhaust blocking-pool threads by sending oversized block locator vectors. Attackers can send getblocks or getheaders messages with up to 65,535 locator hashes, triggering per-hash chain lookups that degrade block validation, RPC, and mempool performance.

Affected products

• Zcashfoundation Zebra: before 4.5.0 (fixed in 4.5.0); before 8.0.0 (fixed in 8.0.0)

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