CVE-2023-32059 is a high-severity (CVSS 7.5) CWE-683 vulnerability in vyper. 1 public exploit reference exists, so weaponization risk is real. O3 Security confirms whether CVE-2023-32059 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Vyper vulnerable to incorrect ordering of arguments for kwargs passed to internal calls
Real-World Exposure
vyperReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
Vyper is a Pythonic smart contract language for the Ethereum virtual machine. Prior to version 0.3.8, internal calls with default arguments are compiled incorrectly. Depending on the number of arguments provided in the call, the defaults are added not right-to-left, but left-to-right. If the types are incompatible, typechecking is bypassed. The ability to pass kwargs to internal functions is an undocumented feature that is not well known about. The issue is patched in version 0.3.8.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | vyper | all versions | 0.3.8 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for vyper. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update vyper to 0.3.8 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-32059 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2023-32059 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2023-32059. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2023-32059 in your dependencies?
O3 detects CVE-2023-32059 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.