Improper input validation in Vyperlang Vyper
CVE-2020-37289
Vyper before 0.3.1 lacks a uint8 type, allowing interface return values declared as uint8, such as ERC20.decimals(), to be stored in uint256 variables without bounds checking. Malicious contracts can return values greater than 255 to manipulate or bypass contract logic that relies on these values.
Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)
Published .
CVSS v3 metric
CVSS v3 base score 3.7 (Low). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- github.com/vyperlang/vyper/security/advisories/GHSA-mr6r-mvw4-736g (vendor-advisory)
- www.vulncheck.com/advisories/vyper-before-0.3.1-improper-input-validation-of-ui… (third-party-advisory)
Frequently asked questions
- What is CVE-2020-37289?
- CVE-2020-37289 is a low-severity vulnerability in Vyperlang Vyper, classified under Improper Input Validation. CVSS score: 3.7/10. Published 2026-10-21.
- How severe is CVE-2020-37289?
- Low severity. CVSS v3 base score is 3.7 out of 10.