What is CVE-2021-41122?

CVE-2021-41122 is a medium-severity vulnerability in Vyperlang Vyper, classified under Incorrect Calculation. CVSS score: 4.3/10. Published 2021-10-05.

How severe is CVE-2021-41122?

Medium severity. CVSS v3 base score is 4.3 out of 10.

Vulnerability in Vyperlang Vyper

CVE-2021-41122

Vyper is a Pythonic Smart Contract Language for the EVM. In affected versions external functions did not properly validate the bounds of decimal arguments. The can lead to logic errors. This issue has been resolved in version 0.3.0.

Published 2021-10-05 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N.

EPSS exploit prediction

EPSS: 0.008 (55.0th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 55th percentile — 55.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.008 · newest: 0.008 · change: 0.000

Affected products

Vyperlang Vyper — versions < 0.3.0

Weakness classification (CWE)

CWE-682 — Incorrect Calculation

References

github.com/vyperlang/vyper/security/advisories/GHSA-c7pr-343r-5c46 (Exploit, Third Party Advisory)
github.com/vyperlang/vyper/pull/2447 (Third Party Advisory)

Frequently asked questions

What is CVE-2021-41122?: CVE-2021-41122 is a medium-severity vulnerability in Vyperlang Vyper, classified under Incorrect Calculation. CVSS score: 4.3/10. Published 2021-10-05.
How severe is CVE-2021-41122?: Medium severity. CVSS v3 base score is 4.3 out of 10.