{"id":"CVE-2023-42441","aliases":["GHSA-3hg2-r75x-g69m","PYSEC-2023-305"],"url":"https://o3.security/vulnerability/CVE-2023-42441","summary":"Vyper has incorrect re-entrancy lock when key is empty string","details":"### Impact\n\nLocks of the type `@nonreentrant(\"\")` or `@nonreentrant('')` do not produce reentrancy checks at runtime.\n\n```Vyper\n@nonreentrant(\"\") # unprotected\n@external\ndef bar():\n    pass\n\n@nonreentrant(\"lock\") # protected\n@external\ndef foo():\n    pass\n```\n### Patches\n\nPatched in #3605\n\n### Workarounds\n\nThe lock name should be a non-empty string.\n\n### References\n_Are there any links users can visit to find out more?_\n","published":"2023-09-18T20:19:26.086Z","modified":"2026-10-28T02:30:35.567176931Z","cvss":{"score":5.3,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":1,"affectedPackages":[{"ecosystem":"PyPI","name":"vyper","fixedVersion":"0.3.10"}],"fix":{"url":"https://github.com/vyperlang/vyper/commit/0b740280c1e3c5528a20d47b29831948ddcc6d83","label":"vyperlang/vyper@0b74028"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/42xxx/CVE-2023-42441.json"},{"type":"ADVISORY","url":"https://github.com/vyperlang/vyper/security/advisories/GHSA-3hg2-r75x-g69m"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-42441"},{"type":"FIX","url":"https://github.com/vyperlang/vyper/commit/0b740280c1e3c5528a20d47b29831948ddcc6d83"},{"type":"FIX","url":"https://github.com/vyperlang/vyper/pull/3605"},{"type":"WEB","url":"https://github.com/pypa/advisory-database/tree/main/vulns/vyper/PYSEC-2023-305.yaml"},{"type":"PACKAGE","url":"https://github.com/vyperlang/vyper"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-10-28T02:30:35.567176931Z"}}