{"id":"GHSA-5824-cm3x-3c38","summary":"Vyper has incorrectly allocated named re-entrancy locks","details":"### Impact\n\nIn versions 0.2.15, 0.2.16 and 0.3.0, named re-entrancy locks are allocated incorrectly. Each function using a named re-entrancy lock gets a unique lock regardless of the key, allowing cross-function re-entrancy in contracts compiled with the susceptible versions. A specific set of conditions is required to result in misbehavior of affected contracts, specifically:\n\n- A `.vy` contract compiled with either of the following `vyper` versions: `0.2.15`, `0.2.16`, `0.3.0`\n- A primary function that utilizes the `@nonreentrant` decorator with a specific `key` and does not strictly follow the check-effects-interaction pattern (i.e. contains an external call to an untrusted party before storage updates)\n- A secondary function that utilizes the same `key` and would be affected by the improper state caused by the primary function\n\n### Patches\nhttps://github.com/vyperlang/vyper/pull/2439, https://github.com/vyperlang/vyper/pull/2514\n\n### Workarounds\nUpgrade to 0.3.1 or higher\n\n### References\nTechnical post-mortem report: https://hackmd.io/@vyperlang/HJUgNMhs2","aliases":["CVE-2023-39363","PYSEC-2023-142"],"modified":"2026-09-10T03:49:57.451549676Z","published":"2023-08-09T14:27:57Z","database_specific":{"github_reviewed":true,"github_reviewed_at":"2023-08-09T14:27:57Z","nvd_published_at":"2023-08-07T19:15:11Z","cwe_ids":["CWE-863"],"severity":"CRITICAL"},"references":[{"type":"WEB","url":"https://github.com/vyperlang/vyper/security/advisories/GHSA-5824-cm3x-3c38"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-39363"},{"type":"WEB","url":"https://github.com/vyperlang/vyper/pull/2439"},{"type":"WEB","url":"https://github.com/vyperlang/vyper/pull/2514"},{"type":"WEB","url":"https://github.com/pypa/advisory-database/tree/main/vulns/vyper/PYSEC-2023-142.yaml"},{"type":"PACKAGE","url":"https://github.com/vyperlang/vyper"},{"type":"WEB","url":"https://hackmd.io/@LlamaRisk/BJzSKHNjn"},{"type":"WEB","url":"https://hackmd.io/@vyperlang/HJUgNMhs2"}],"affected":[{"package":{"name":"vyper","ecosystem":"PyPI","purl":"pkg:pypi/vyper"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0.2.15"},{"fixed":"0.3.1"}]}],"versions":["0.2.15","0.2.16","0.3.0"],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2023/08/GHSA-5824-cm3x-3c38/GHSA-5824-cm3x-3c38.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:H"},{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:H/SA:H/E:A"}]}