CVE-2023-30542: Openzeppelin Contracts

High severity, CVSS 8.8. EPSS: 0.6% chance of exploitation in the next 30 days.

OpenZeppelin Contracts is a library for secure smart contract development. The proposal creation entrypoint (`propose`) in `GovernorCompatibilityBravo` allows the creation of proposals with a `signatures` array shorter than the `calldatas` array. This causes the additional elements of the latter to be ignored, and if the proposal succeeds the corresponding actions would eventually execute without any calldata. The `ProposalCreated` event correctly represents what will eventually execute, but the proposal parameters as queried through `getActions` appear to respect the original intended calldata. This issue has been patched in 4.8.3. As a workaround, ensure that all proposals that pass through governance have equal length `signatures` and `calldatas` parameters.

Affected products

• Openzeppelin Contracts: from 4.3.0, before 4.8.3 (fixed in 4.8.3)
• Openzeppelin Contracts Upgradeable: from 4.3.0, before 4.8.3 (fixed in 4.8.3)

Published 2023-04-16. Last modified 2026-06-17.