CVE-2021-46320

Name: CVE-2021-46320
Creator: NVD / NIST
Published: 2022-02-04T12:15:07.623+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 1.17%

Last modified Jun 17, 2026

CVE-2021-46320 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. In OpenZeppelin <=v4.4.0, initializer functions that are invoked separate from contract creation (the most prominent example being minimal proxies) may be reentered if they make an untrusted non-view external call. Once an initializer has finished running it can never be re-executed. EPSS estimates a 1.17% chance of exploitation in the next 30 days.

Description

In OpenZeppelin <=v4.4.0, initializer functions that are invoked separate from contract creation (the most prominent example being minimal proxies) may be reentered if they make an untrusted non-view external call. Once an initializer has finished running it can never be re-executed. However, an exception put in place to support multiple inheritance made reentrancy possible, breaking the expectation that there is a single execution.

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

EPSS Probability

1.17%

63.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-665

Affected Software

Vendor	Product	Versions
Openzeppelin	Openzeppelin	>= 3.2.0, <= 4.4.0

References

https://github.com/OpenZeppelin/openzeppelin-contracts/security/advisories/GHSA-9c22-pwxw-p6hxThird Party Advisory
https://github.com/OpenZeppelin/openzeppelin-contracts/security/advisories/GHSA-9c22-pwxw-p6hxThird Party Advisory

Timeline

Published: Feb 4, 2022
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-46320?

How severe is CVE-2021-46320?

CVE-2021-46320 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 1.17% probability of exploitation in the next 30 days.

How do I fix CVE-2021-46320?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-46320?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST