{"cve":"CVE-2023-40014","nvd":{"published":"2023-08-10T20:15:10.867","modified":"2026-06-17T06:15:45.027","status":"Modified","description":"OpenZeppelin Contracts is a library for secure smart contract development. Starting in version 4.0.0 and prior to version 4.9.3, contracts using `ERC2771Context` along with a custom trusted forwarder may see `_msgSender` return `address(0)` in calls that originate from the forwarder with calldata shorter than 20 bytes. This combination of circumstances does not appear to be common, in particular it is not the case for `MinimalForwarder` from OpenZeppelin Contracts, or any deployed forwarder the team is aware of, given that the signer address is appended to all calls that originate from these forwarders. The problem has been patched in v4.9.3.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","score":5.3},"cwes":["CWE-116"],"references":["https://github.com/OpenZeppelin/openzeppelin-contracts/commit/9445f96223041abf2bf08daa56f8da50b674cbcd","https://github.com/OpenZeppelin/openzeppelin-contracts/commit/e4435eed757d4309436b1e06608e97b6d6e2fdb5","https://github.com/OpenZeppelin/openzeppelin-contracts/pull/4481","https://github.com/OpenZeppelin/openzeppelin-contracts/pull/4484","https://github.com/OpenZeppelin/openzeppelin-contracts/releases/tag/v4.9.3"],"products":["openzeppelin:openzeppelin_contracts","openzeppelin:openzeppelin_contracts-upgradable"],"source":"nvd","synced_at":"2026-10-19T21:39:14.809778102+00:00"},"epss":{"cve":"CVE-2023-40014","score":0.00743,"percentile":0.54715,"date":"2026-11-01"},"kev":null,"osv":[{"id":"GHSA-g4vp-m682-qqmp","url":"https://osv.dev/vulnerability/GHSA-g4vp-m682-qqmp","summary":"OpenZeppelin Contracts vulnerable to Improper Escaping of Output","modified":"2023-11-08T04:13:16.291927Z","packages":[{"ecosystem":"npm","name":"@openzeppelin/contracts","purl":"pkg:npm/%40openzeppelin/contracts","ranges":[">=4.0.0 <4.9.3"],"fixed":["4.9.3"]},{"ecosystem":"npm","name":"@openzeppelin/contracts-upgradeable","purl":"pkg:npm/%40openzeppelin/contracts-upgradeable","ranges":[">=4.0.0 <4.9.3"],"fixed":["4.9.3"]}]}],"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."]}