CVE-2025-47285

Vyper is the Pythonic Programming Language for the Ethereum Virtual Machine. In versions up to and including 0.4.2rc1, concat may skip evaluation of side effects when the length of an argument is zero. This is due to a fastpath in the implementation which skips evaluation of argument expressions...

CVE-2025-47285 Vyper's `concat()` builtin may elide side-effects for zero-length arguments

Vyper is the Pythonic Programming Language for the Ethereum Virtual Machine. In versions up to and including 0.4.2rc1, concat may skip evaluation of side effects when the length of an argument is zero. This is due to a fastpath in the implementation which skips evaluation of argument expressions...

PT-2025-21347

Name of the Vulnerable Software and Affected Versions: Vyper versions up to and including 0.4.2rc1 Description: The issue arises from the concat function potentially skipping the evaluation of side effects when the length of an argument is zero. This is due to a fastpath in the implementation tha...