CVE-2021-41122: Bounds check missing for decimal args in Vyper

Severity: medium (CVSS 4.0 v2.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.8% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2021-10-05 · updated 2026-06-17
Weakness: CWE-682

Description

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.

Affected products

vyperlang vyper: before 0.3.0 — fixed in 0.3.0

How to fix

Upgrade to a fixed version: vyperlang vyper 0.3.0. Check the vendor advisory for mitigations.

References

https://github.com/vyperlang/vyper/pull/2447
https://github.com/vyperlang/vyper/security/advisories/GHSA-c7pr-343r-5c46
https://github.com/vyperlang/vyper/pull/2447
https://github.com/vyperlang/vyper/security/advisories/GHSA-c7pr-343r-5c46

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