CVE-2020-37289 Vyper before 0.3.1 Improper Input Validation of uint8 Interface Return Values
- Exploited in the wild
- Not known
- Fix
- None listed
What is CVE-2020-37289?
CVE-2020-37289 is a medium-severity vulnerability in vyperlang vyper, published on 21 Oct 2026.
Official description
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.
Weakness: CWE-20
Which versions are affected by CVE-2020-37289?
2 open source packages ship an affected version, including vyper.
| Package | Affected | Fixed in |
|---|---|---|
vyper PyPI | All versions to 0.1.0b16 | None |
vyper PyPI | All versions to 0.1.0b16 | None |
How do I fix CVE-2020-37289?
No fix has been published for CVE-2020-37289 yet. Limit exposure of the affected software until one is available.
Is CVE-2020-37289 being exploited?
There is no known exploitation of CVE-2020-37289 in the wild and no public exploit code.
Sources
Also known as GHSA-6j8p-r676-fv69, GHSA-mr6r-mvw4-736g.