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🐍 PyPI

CVE-2023-32058

HIGH

Vyper vulnerable to integer overflow in loop

Also known asGHSA-6r8q-pfpv-7cgjPYSEC-2023-78
Published
May 11, 2023
Updated
Apr 10, 2026
Affected
1 pkg
Patched
1 / 1
Exploits
1 known

EPSS Exploitation Probability

via FIRST.org ↗
0.9%probability of exploitation in next 30 days
Lower Risk55th percentile+0.44%
0.00%0.47%0.94%1.41%0.2%0.9%Dec 25Apr 26Jun 26

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

1 pkg affected
🐍vyper

Real-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, due to missing overflow check for loop variables, by assigning the iterator of a loop to a variable, it is possible to overflow the type of the latter. The issue seems to happen only in loops of type for i in range(a, a + N) as in loops of type for i in range(start, stop) and for i in range(stop), the compiler is able to raise a TypeMismatch when trying to overflow the variable. The problem has been patched in version 0.3.8.

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
🐍PyPIvyperall versions0.3.8
Exploits & PoCs
1

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 dependency
  1. Detect

    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.

  2. Fix

    Update vyper to 0.3.8 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-32058 is resolved across your whole dependency graph.

  3. 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.

  4. How O3 protects you

    O3 pinpoints whether CVE-2023-32058 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-2023-32058. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

Vyper is a Pythonic smart contract language for the Ethereum virtual machine. Prior to version 0.3.8, due to missing overflow check for loop variables, by assigning the iterator of a loop to a variable, it is possible to overflow the type of the latter. The issue seems to happen only in loops of type `for i in range(a, a + N)` as in loops of type `for i in range(start, stop)` and `for i in range(stop)`, the compiler is able to raise a `TypeMismatch` when trying to overflow the variable. The problem has been patched in version 0.3.8.
O3 Security · Impact-Aware SCA

Is CVE-2023-32058 in your dependencies?

O3 detects CVE-2023-32058 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.