{"id":"CVE-2023-32059","aliases":["GHSA-ph9x-4vc9-m39g","PYSEC-2023-79"],"url":"https://o3.security/vulnerability/CVE-2023-32059","summary":"Vyper vulnerable to incorrect ordering of arguments for kwargs passed to internal calls","details":"### Impact\n\nInternal calls to internal functions with more than 1 default argument are compiled incorrectly. Depending on the number of arguments\nprovided in the call, the defaults are added not right-to-left, but left-to-right. If the types are incompatible,\ntypechecking is bypassed. In the `bar()` function in the following code, `self.foo(13)` is compiled to\n`self.foo(13,12)` instead of `self.foo(13,1337)`.\n\n```vyper\n@internal\ndef foo(a:uint256 = 12, b:uint256 = 1337):\n    pass\n\n@internal\ndef bar():\n    self.foo(13)\n```\n\nnote that at the time of publication, the ability to pass kwargs to internal functions is an undocumented feature that does not seem to be widely used.\n\n### Patches\npatched in c3e68c302aa6e1429946473769dd1232145822ac\n\n### Workarounds\n_Is there a way for users to fix or remediate the vulnerability without upgrading?_\n\n### References\n_Are there any links users can visit to find out more?_\n","published":"2023-05-11T21:01:11.456Z","modified":"2026-08-12T03:51:11.407761617Z","cvss":{"score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":1,"affectedPackages":[{"ecosystem":"PyPI","name":"vyper","fixedVersion":"0.3.8"}],"fix":{"url":"https://github.com/vyperlang/vyper/commit/c3e68c302aa6e1429946473769dd1232145822ac","label":"vyperlang/vyper@c3e68c3"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/32xxx/CVE-2023-32059.json"},{"type":"ADVISORY","url":"https://github.com/vyperlang/vyper/security/advisories/GHSA-ph9x-4vc9-m39g"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-32059"},{"type":"FIX","url":"https://github.com/vyperlang/vyper/commit/c3e68c302aa6e1429946473769dd1232145822ac"},{"type":"WEB","url":"https://github.com/pypa/advisory-database/tree/main/vulns/vyper/PYSEC-2023-79.yaml"},{"type":"PACKAGE","url":"https://github.com/vyperlang/vyper"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:11.407761617Z"}}