Out-of-bounds Write Affecting vyper package, versions [0.2.13,0.2.15)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-PYTHON-VYPER-22132610
- published2 Nov 2026
- disclosed21 Oct 2026
- creditUnknown
Introduced: 21 Oct 2026
NewCVE-2021-48018 (opens in a new tab)How to fix?
Upgrade vyper to version 0.2.15 or higher.
Overview
vyper is a Pythonic Smart Contract Language for the EVM.
Affected versions of this package are vulnerable to Out-of-bounds Write via incorrect storage slot allocation for reentrancy locks in the get_nonreentrant_lock function. When the @nonreentrant decorator is used, the reentrancy protection key is allocated to the same storage slot as a regular storage variable, causing the reentrancy lock to overwrite and corrupt contract storage variables. An attacker can exploit this corruption to bypass reentrancy guards or manipulate storage state in contracts that use the @nonreentrant decorator.
Note: This is only exploitable in contracts that use the @nonreentrant decorator alongside storage variables.