Always-Incorrect Control Flow Implementation Affecting vyper package, versions [0.1.0b10,0.2.3)
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- published24 Oct 2026
- disclosed6 Oct 2026
- creditUnknown
Introduced: 6 Oct 2026
New CVE NOT AVAILABLE CWE-670 (opens in a new tab)How to fix?
Upgrade vyper to version 0.2.3 or higher.
Overview
vyper is a Pythonic Smart Contract Language for the EVM.
Affected versions of this package are vulnerable to Always-Incorrect Control Flow Implementation in make_return_stmt in vyper/codegen/return_.py when a return statement is executed inside a for loop, the loop's values are not popped from the stack before the function returns. This leaves the EVM stack in a corrupted state, causing incorrect behavior or a crash in contracts that use return inside a loop body.
Note: This is only exploitable in contracts that use return statements inside for loops, particularly in combination with nested calls.