{"cve":"CVE-2023-46247","nvd":{"published":"2023-12-13T20:15:49.360","modified":"2026-06-17T06:30:30.753","status":"Modified","description":"Vyper is a Pythonic Smart Contract Language for the Ethereum Virtual Machine (EVM). Contracts containing large arrays might underallocate the number of slots they need by 1. Prior to v0.3.8, the calculation to determine how many slots a storage variable needed used `math.ceil(type_.size_in_bytes / 32)`. The intermediate floating point step can produce a rounding error if there are enough bits set in the IEEE-754 mantissa. Roughly speaking, if `type_.size_in_bytes` is large (> 2**46), and slightly less than a power of 2, the calculation can overestimate how many slots are needed by 1. If `type_.size_in_bytes` is slightly more than a power of 2, the calculation can underestimate how many slots are needed by 1. This issue is patched in version 0.3.8.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","score":7.5},"cwes":["CWE-193","CWE-682"],"references":["https://github.com/vyperlang/vyper/blob/6020b8bbf66b062d299d87bc7e4eddc4c9d1c157/vyper/semantics/validation/data_positions.py#L197","https://github.com/vyperlang/vyper/commit/0bb7203b584e771b23536ba065a6efda457161bb","https://github.com/vyperlang/vyper/security/advisories/GHSA-6m97-7527-mh74","https://github.com/vyperlang/vyper/blob/6020b8bbf66b062d299d87bc7e4eddc4c9d1c157/vyper/semantics/validation/data_positions.py#L197","https://github.com/vyperlang/vyper/commit/0bb7203b584e771b23536ba065a6efda457161bb"],"products":["vyperlang:vyper"],"source":"nvd","synced_at":"2026-10-19T21:42:34.585441961+00:00"},"epss":{"cve":"CVE-2023-46247","score":0.00692,"percentile":0.52887,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-6m97-7527-mh74","url":"https://osv.dev/vulnerability/GHSA-6m97-7527-mh74","summary":"incorrect storage layout for contracts containing large arrays","modified":"2026-09-10T03:49:59.391185148Z","packages":[{"ecosystem":"PyPI","name":"vyper","purl":"pkg:pypi/vyper","ranges":["<0.3.8"],"fixed":["0.3.8"]}]},{"id":"PYSEC-2023-307","url":"https://osv.dev/vulnerability/PYSEC-2023-307","summary":"","modified":"2024-11-21T14:57:14.392433Z","packages":[{"ecosystem":"PyPI","name":"vyper","purl":"pkg:pypi/vyper","ranges":["<0.3.8"],"fixed":["0.3.8"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}