Quick answers
- Is CVE-2020-37287 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2020-37287 being exploited in the wild.
- How severe is CVE-2020-37287?
- Medium severity, with a CVSS score of 5.9, published 21 October 2026.
- Which products and versions are affected?
- Vyper before 0.2.6.
- Is there a fix for CVE-2020-37287?
- Yes: fixed in 0.2.6. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2020-37287 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2020-37287?
- Check whether you run Vyper at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
How to fix
- Fixed in: 0.2.6
Technical details
The vulnerability is a call stack management bug in the Vyper compiler: it assumes all subtypes within arrays or structs occupy exactly 32 bytes, but this assumption is false for non-base types. When complex types are passed to internal or external functions, the compiler generates incorrect stack layout code, leading to data corruption. Exploitation requires the attacker to deploy a malicious contract or call a vulnerable contract with crafted arguments.
Affected products
- Vyper Vyper before 0.2.6
Timeline
- 2020-10-10: disclosed
- 2020-10-10: patched