{"cve":"CVE-2021-39167","nvd":{"published":"2021-08-27T00:15:06.970","modified":"2026-06-17T04:03:14.070","status":"Modified","description":"OpenZepplin is a library for smart contract development. In affected versions a vulnerability in TimelockController allowed an actor with the executor role to escalate privileges. Further details about the vulnerability will be disclosed at a later date. As a workaround revoke the executor role from accounts not strictly under the team's control. We recommend revoking all executors that are not also proposers. When applying this mitigation, ensure there is at least one proposer and executor remaining.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","score":9.8},"cwes":["CWE-269"],"references":["https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/CHANGELOG.md#431","https://github.com/OpenZeppelin/openzeppelin-contracts/commit/cec4f2ef57495d8b1742d62846da212515d99dd5","https://github.com/OpenZeppelin/openzeppelin-contracts/security/advisories/GHSA-fg47-3c2x-m2wr","https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/CHANGELOG.md#431","https://github.com/OpenZeppelin/openzeppelin-contracts/commit/cec4f2ef57495d8b1742d62846da212515d99dd5"],"products":["openzeppelin:contracts"],"source":"nvd","synced_at":"2026-10-19T21:21:57.125947417+00:00"},"epss":{"cve":"CVE-2021-39167","score":0.0159,"percentile":0.75659,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-fg47-3c2x-m2wr","url":"https://osv.dev/vulnerability/GHSA-fg47-3c2x-m2wr","summary":"TimelockController vulnerability in OpenZeppelin Contracts ","modified":"2026-07-08T06:29:37.864167374Z","packages":[{"ecosystem":"npm","name":"@openzeppelin/contracts","purl":"pkg:npm/%40openzeppelin/contracts","ranges":[">=4.0.0 <4.3.1"],"fixed":["4.3.1"]},{"ecosystem":"npm","name":"@openzeppelin/contracts","purl":"pkg:npm/%40openzeppelin/contracts","ranges":[">=3.3.0 <3.4.2"],"fixed":["3.4.2"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}