CVE-2020-37287
mediumpriority · track · 24EPSS 0.003 · 17 %ileUSEPSS · scored 2026-10-28
Vyper before 0.2.6 contains a call stack corruption vulnerability that causes incorrect function outputs when complex types with non-base members are passed as arguments. Contracts passing multi-dimensional arrays or structs to internal or external functions receive corrupted values because the compiler assumed each subtype size is 32.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 4.6–8.2
weaknesses
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affected products (1)
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advisories (1)
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- GHSA-4v7v-gqf9-ww2gVyper: Call stack corruption when passing complex type containing non-base type members as argument2026-10-06ghsa · osvUS
### Impact When we pass a multi-dimensional array (like `[[1, 2], [3, 4]]`) as an argument to internal/external functions we get incorrect output. This is due to a stack management issue, because it was assumed that the size of each subtype of an array/struct is 32, which is not always correct. Example code: ```python @internal def test_input(arr: int128[2][1], i: int128) -> (int128[2][1], int128): return arr, i @external def test_values(arr: int128[2][1], i: int128) -> (int128[2][1], int128): return self.test_input(arr, i) ``` Please see #2183 for further information ### Patches This problem was fixed in #2184, and released as a part of [`v0.2.6`](https://github.com/vyperlang/vyper/releases/tag/v0.2.6).
sources
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references (2) nvd
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