CVE-2024-32647: vyper performs double eval of raw_args in create_from_blueprint

Severity: medium (CVSS 5.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-04-25 · updated 2026-06-17
Weakness: CWE-95

Description

Vyper is a pythonic Smart Contract Language for the Ethereum virtual machine. In versions 0.3.10 and prior, using the `create_from_blueprint` builtin can result in a double eval vulnerability when `raw_args=True` and the `args` argument has side-effects. It can be seen that the `_build_create_IR` function of the `create_from_blueprint` builtin doesn't cache the mentioned `args` argument to the stack. As such, it can be evaluated multiple times (instead of retrieving the value from the stack). 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 exist.

Affected products

vyperlang vyper: before 0.4.0 — fixed in 0.4.0

How to fix

Upgrade to a fixed version: vyperlang vyper 0.4.0. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2024-32647 or the next vulnerability affects your stack