CVE-2023-31146

Name: CVE-2023-31146
Creator: NVD / NIST
Published: 2023-05-11T21:15:10.24+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.1/10EPSS 1.24%

Last modified Jun 17, 2026

CVE-2023-31146 is a critical-severity vulnerability rated 9.1/10 on the CVSS scale. Vyper is a Pythonic smart contract language for the Ethereum virtual machine. Prior to version 0.3.8, during codegen, the length word of a dynarray is written before the data, which can result in out-of-bounds array access in the case where the dynarray is on both the lhs and rhs of an assignment. EPSS estimates a 1.24% chance of exploitation in the next 30 days.

Description

Vyper is a Pythonic smart contract language for the Ethereum virtual machine. Prior to version 0.3.8, during codegen, the length word of a dynarray is written before the data, which can result in out-of-bounds array access in the case where the dynarray is on both the lhs and rhs of an assignment. The issue can cause data corruption across call frames. The expected behavior is to revert due to out-of-bounds array access. Version 0.3.8 contains a patch for this issue.

Metrics

CVSS 3.1

9.1/10

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

EPSS Probability

1.24%

65.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Vyperlang	Vyper	< 0.3.8

References

https://github.com/vyperlang/vyper/commit/4f8289a81206f767df1900ac48f485d90fc87edbPatch
https://github.com/vyperlang/vyper/security/advisories/GHSA-3p37-3636-q8wvExploit, Vendor Advisory
https://github.com/vyperlang/vyper/commit/4f8289a81206f767df1900ac48f485d90fc87edbPatch
https://github.com/vyperlang/vyper/security/advisories/GHSA-3p37-3636-q8wvExploit, Vendor Advisory

Timeline

Published: May 11, 2023
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2023-31146?

How severe is CVE-2023-31146?

CVE-2023-31146 has a CVSS score of 9.1/10 (CRITICAL severity). The EPSS model estimates a 1.24% probability of exploitation in the next 30 days.

How do I fix CVE-2023-31146?

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-2023-31146?

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

Scan your code now

Source: NVD / NIST