VULNERABILITY INTELLIGENCE
CVE-2021-41264
CVSS score9.8 CRITICAL
EPSS probability1.49%
CISA KEVNot currently listed
Published2021-11-12
Last modified2026-06-17
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Description
OpenZeppelin Contracts is a library for smart contract development. In affected versions upgradeable contracts using `UUPSUpgradeable` may be vulnerable to an attack affecting uninitialized implementation contracts. A fix is included in version 4.3.2 of `@openzeppelin/contracts` and `@openzeppelin/contracts-upgradeable`. For users unable to upgrade; initialize implementation contracts using `UUPSUpgradeable` by invoking the initializer function (usually called `initialize`). An example is provided [in the forum](https://forum.openzeppelin.com/t/security-advisory-initialize-uups-implementation-contracts/15301).
Weakness classification
- security-advisories@github.com: CWE-665
Primary references
- security-advisories@github.com — Issue Tracking, Mitigation, Patch, Vendor Advisory
- security-advisories@github.com — Patch, Third Party Advisory
- security-advisories@github.com — Third Party Advisory
- af854a3a-2127-422b-91ae-364da2661108 — Issue Tracking, Mitigation, Patch, Vendor Advisory
- af854a3a-2127-422b-91ae-364da2661108 — Patch, Third Party Advisory
- af854a3a-2127-422b-91ae-364da2661108 — Third Party Advisory