CVE-2023-23940: Openzeppelin Contracts

Medium severity, CVSS 5.3. EPSS: 0.2% chance of exploitation in the next 30 days.

OpenZeppelin Contracts for Cairo is a library for secure smart contract development written in Cairo for StarkNet, a decentralized ZK Rollup. `is_valid_eth_signature` is missing a call to `finalize_keccak` after calling `verify_eth_signature`. As a result, any contract using `is_valid_eth_signature` from the account library (such as the `EthAccount` preset) is vulnerable to a malicious sequencer. Specifically, the malicious sequencer would be able to bypass signature validation to impersonate an instance of these accounts. The issue has been patched in 0.6.1.

Affected products

• Openzeppelin Contracts: from 0.2.0, before 0.6.1 (fixed in 0.6.1)

Published 2023-02-03. Last modified 2026-06-17.