CVE-2023-30542: OpenZeppelin Contracts is a library for secure smart contract development. The proposal creation entrypoint (`propose`) in `GovernorCompatibilityBravo...

Description

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.

Metrics

CVSS 3.1

8.8/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

0.58%

43.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-20

Affected Software

Vendor	Product	Versions
Openzeppelin	Contracts	>= 4.3.0, < 4.8.3
Openzeppelin	Contracts Upgradeable	>= 4.3.0, < 4.8.3

References

Timeline

Published: Apr 16, 2023
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2023-30542?

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.

How severe is CVE-2023-30542?

CVE-2023-30542 has a CVSS score of 8.8/10 (HIGH severity). The EPSS model estimates a 0.58% probability of exploitation in the next 30 days.

How do I fix CVE-2023-30542?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.