{"id":"CVE-2023-34234","aliases":["GHSA-5h3x-9wvq-w4m2"],"url":"https://o3.security/vulnerability/CVE-2023-34234","summary":"Governor proposal creation may be blocked by frontrunning in OpenZeppelin","details":" OpenZeppelin Contracts is a library for smart contract development. By frontrunning the creation of a proposal, an attacker can become the proposer and gain the ability to cancel it. The attacker can do this repeatedly to try to prevent a proposal from being proposed at all. This impacts the `Governor` contract in v4.9.0 only, and the `GovernorCompatibilityBravo` contract since v4.3.0. This problem has been patched in 4.9.1 by introducing opt-in frontrunning protection. Users are advised to upgrade. Users unable to upgrade may submit the proposal creation transaction to an endpoint with frontrunning protection as a workaround.","published":"2023-06-07T17:06:10.154Z","modified":"2026-07-16T03:46:24.196782497Z","cvss":{"score":5.3,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"npm","name":"@openzeppelin/contracts","fixedVersion":"4.9.1"},{"ecosystem":"npm","name":"@openzeppelin/contracts-upgradeable","fixedVersion":"4.9.1"}],"fix":{"url":"https://github.com/OpenZeppelin/openzeppelin-contracts/commit/d9474327a492f9f310f31bc53f38dbea56ed9a57","label":"OpenZeppelin/openzeppelin-contracts@d947432"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/34xxx/CVE-2023-34234.json"},{"type":"ADVISORY","url":"https://github.com/OpenZeppelin/openzeppelin-contracts/security/advisories/GHSA-5h3x-9wvq-w4m2"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-34234"},{"type":"FIX","url":"https://github.com/OpenZeppelin/openzeppelin-contracts/commit/d9474327a492f9f310f31bc53f38dbea56ed9a57"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-07-16T03:46:24.196782497Z"}}