AIKIDO-2026-844958
zebrad is vulnerable to Denial of Service (DoS)
59
Medium Risk
This Affects:
zebradTL;DR
During contextual block verification Zebra checks the remaining transparent value of every non-coinbase transaction. The implementation clones and converts the entire block-level spent-output map once per transaction instead of passing each transaction only the outputs it spends, turning a linear check into quadratic work. A single valid mined block packed with minimal single-input transactions can stall block processing for tens of seconds. The fix gives each transaction only its own spent outputs and avoids the extra copies, making the check linear.
Who does this affect?
You are affected if you are using a version that falls within the vulnerable range and your node validates blocks, which every default full-node configuration does. The stall is triggered by a specially crafted valid, proof-of-work-bearing block, so it cannot be induced by an unmined block from an arbitrary peer.
Background info
zebrad is vulnerable to Denial of Service (DoS) in versions 0.0.1 - 6.0.0.
How to fix this
Upgrade the zebrad library to the patch version.
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SOC 2Compliant
ISO 27001Compliant