# OpenZeppelin Contracts GovernorCompatibilityBravo incorrect ABI encoding

Source: https://junglewise.ai/threats/openzeppelin-contracts-governorcompatibilitybravo-incorrect-abi-33a7ac83  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2022-01-13. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

Severity: info · Published 2022-01-13

OpenZeppelin Contracts is a widely-used library for building secure smart contracts on blockchain platforms. The GovernorCompatibilityBravo module, which implements governance voting and proposal execution, may incorrectly encode function arguments when proposals are created using explicit function signatures. This could cause governance proposals to execute with wrong parameters, potentially resulting in unintended contract state changes or logic execution.

Technologies: [@openzeppelin/contracts (npm)](https://junglewise.ai/threats/technologies/openzeppelin-contracts), [@openzeppelin/contracts-upgradeable (npm)](https://junglewise.ai/threats/technologies/openzeppelin-contracts-upgradeable), [OpenZeppelin Contracts](https://junglewise.ai/threats/technologies/contracts), [OpenZeppelin Contracts Upgradeable](https://junglewise.ai/threats/technologies/contracts-upgradeable). Vendors: [npm](https://junglewise.ai/threats/vendors/npm), [OpenZeppelin](https://junglewise.ai/threats/vendors/openzeppelin).

## Quick answers

**Is This vulnerability exploited in the wild?** No. Junglewise Threat Intelligence has no report of This vulnerability being exploited in the wild.

**How severe is This vulnerability?** Informational severity, published 13 January 2022.

**Which products and versions are affected?** @openzeppelin/contracts (npm) SEMVER:introduced=4.3.0,fixed=4.4.2; @openzeppelin/contracts-upgradeable (npm) SEMVER:introduced=4.3.0,fixed=4.4.2; OpenZeppelin Contracts 4.3.0 through 4.4.1; OpenZeppelin Contracts Upgradeable 4.3.0 through 4.4.1.

**Is there a fix for This vulnerability?** Yes. @openzeppelin/contracts (npm): upgrade to 4.4.2 or later; @openzeppelin/contracts-upgradeable (npm): upgrade to 4.4.2 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is This vulnerability attacked?** It is attacked with local access, in a software library.

**Am I affected?** Check whether you run @openzeppelin/contracts (npm), @openzeppelin/contracts-upgradeable (npm), OpenZeppelin Contracts or one of the others listed at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- @openzeppelin/contracts (npm): upgrade to 4.4.2 or later

  ```sh
  npm install @openzeppelin/contracts@4.4.2
  ```

- @openzeppelin/contracts-upgradeable (npm): upgrade to 4.4.2 or later

  ```sh
  npm install @openzeppelin/contracts-upgradeable@4.4.2
  ```


## Technical details

The vulnerability exists in the GovernorCompatibilityBravo contract's ABI encoding logic when proposals are created with explicit function signatures (e.g., "foo(uint256)") rather than pre-encoded function selectors. When a proposal is created using the signatures parameter, the contract incorrectly encodes the provided calldata, leading to function calls with incorrect arguments. The attack vector requires local control of proposal creation; no network or authentication bypass is needed. An attacker controlling proposal submission can craft proposals that execute unintended logic. This issue affects versions 4.3.0 through 4.4.1; it was patched in v4.4.2. Proposal creation through the Tally platform or OpenZeppelin Defender is not affected.

## Affected products

- OpenZeppelin Contracts 4.3.0 through 4.4.1
- OpenZeppelin Contracts Upgradeable 4.3.0 through 4.4.1

## Timeline

- 2022-01-11: disclosed: Advisory published
- 2022-01-13: patched: Version 4.4.2 released with fix

## References

- [https://github.com/OpenZeppelin/openzeppelin-contracts/security/advisories/GHSA-m6w8-fq7v-ph4m](https://github.com/OpenZeppelin/openzeppelin-contracts/security/advisories/GHSA-m6w8-fq7v-ph4m)
- [https://github.com/OpenZeppelin/openzeppelin-contracts](https://github.com/OpenZeppelin/openzeppelin-contracts)

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