CVE-2024-32646: Vyperlang Vyper

Medium severity, CVSS 5.3. EPSS: 0.5% chance of exploitation in the next 30 days.

Vyper is a pythonic Smart Contract Language for the Ethereum virtual machine. In versions 0.3.10 and prior, using the `slice` builtin can result in a double eval vulnerability when the buffer argument is either `msg.data`, `self.code` or `<address>.code` and either the `start` or `length` arguments have side-effects. It can be easily triggered only with the versions `<0.3.4` as `0.3.4` introduced the unique symbol fence. No vulnerable production contracts were found. Additionally, double evaluation of side-effects should be easily discoverable in client tests. As such, the impact is low. As of time of publication, no fixed versions are available.

Affected products

• Vyperlang Vyper: before 0.4.0 (fixed in 0.4.0)

Published 2024-04-25. Last modified 2026-06-17.