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OpenAdvisories
Low · 2.3 CVE-2025-27105 EUVD-2025-4283GHSA-4w26-8p97-f4jpPYSEC-2025-31

AugAssign evaluation order causing OOB write within the object in Vyper

Published Feb 21, 2025 · Updated Feb 22, 2025 · Assigned by GitHub_M

Description

vyper is a Pythonic Smart Contract Language for the EVM. Vyper handles AugAssign statements by first caching the target location to avoid double evaluation. However, in the case when target is an access to a DynArray and the rhs modifies the array, the cached target will evaluate first, and the bounds check will not be re-evaluated during the write portion of the statement. This issue has been addressed in version 0.4.1 and all users are advised to upgrade. There are no known workarounds for this vulnerability.

Affected products

VendorProductAffectedFixed
vyperlang vyper < 0.4.1 —

Affected packages

EcosystemPackageAffectedFixedRecord
PyPI vyper < 0.4.1 0.4.1 GHSA-4w26-8p97-f4jp

References