CVE-2026-104426

Description

Zebra before 6.1.0 contains an inefficient algorithmic complexity vulnerability in remaining_transaction_value that clones the entire block-level spent-UTXO map per transaction during contextual verification. Attackers can mine or seed the mempool with roughly 26,000 minimal single-input transactions in one block, stalling every validating node for over 52 seconds.

CVSS Vector

References

• https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-4g24-549m-hp75
• https://www.vulncheck.com/advisories/zebra-before-6.1.0-quadratic-complexity-dos-via-block-transparent-value-check