Vyper incorrectly allocated named re-entrancy locks

{
  "id": "efcda54db882f0c1b32e2ae8538576eff4bb54563a125ae26d10efa45744bebb",
  "url": "https://osv.dev/vulnerability/CVE-2023-39363",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Vyper incorrectly allocated named re-entrancy locks",
    "summary": "Vyper is a Pythonic Smart Contract Language for the Ethereum Virtual Machine (EVM). In 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: a `.vy` contract compiled with `vyper` versions `0.2.15`, `0.2.16`, or `0.3.0`; 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); and a secondary function that utilizes the same `key` and would be affected by the improper state caused by the primary function. Version 0.3.1 contains a fix for this issue.",
    "evidence": "osv:CVE-2023-39363",
    "products": [],
    "severity": "critical",
    "structured": {
      "id": "CVE-2023-39363",
      "aliases": [
        "CVE-2023-39363",
        "GHSA-5824-cm3x-3c38",
        "PYSEC-2023-142"
      ],
      "metrics": [
        {
          "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"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/vyperlang/vyper",
              "type": "GIT",
              "events": [
                {
                  "introduced": "6e7dba7a8b5f29762d3470da4f44634b819c808d"
                },
                {
                  "last_affected": "8a23febbb2d523f3701f9a7d0aaf361c104a2a37"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "= 0.2.15"
                      },
                      {
                        "last_affected": "= 0.2.15"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandaloneSingleVersion"
                  },
                  {
                    "range": [
                      {
                        "introduced": "= 0.2.16"
                      },
                      {
                        "last_affected": "= 0.2.16"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandaloneSingleVersion"
                  },
                  {
                    "range": [
                      {
                        "introduced": "= 0.3.0"
                      },
                      {
                        "last_affected": "= 0.3.0"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandaloneSingleVersion"
                  },
                  {
                    "cpe": "cpe:2.3:a:vyperlang:vyper:0.2.15:*:*:*:*:python:*:*",
                    "range": [
                      {
                        "introduced": "0.2.15"
                      },
                      {
                        "last_affected": "0.2.15"
                      }
                    ],
                    "source": "CPE_STRING"
                  },
                  {
                    "cpe": "cpe:2.3:a:vyperlang:vyper:0.2.16:*:*:*:*:python:*:*",
                    "range": [
                      {
                        "introduced": "0.2.16"
                      },
                      {
                        "last_affected": "0.2.16"
                      }
                    ],
                    "source": "CPE_STRING"
                  },
                  {
                    "cpe": "cpe:2.3:a:vyperlang:vyper:0.3.0:*:*:*:*:python:*:*",
                    "range": [
                      {
                        "introduced": "0.3.0"
                      },
                      {
                        "last_affected": "0.3.0"
                      }
                    ],
                    "source": "CPE_STRING"
                  }
                ]
              }
            }
          ],
          "versions": [
            "0.2.15",
            "0.2.16",
            "0.3.0",
            "= 0.2.15",
            "= 0.2.16",
            "= 0.3.0",
            "v0.3.0",
            "v0.2.16",
            "v0.2.15"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2023-39363.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:30.076966957Z",
      "provider": "osv",
      "references": [
        "https://hackmd.io/@LlamaRisk/BJzSKHNjn",
        "https://hackmd.io/@vyperlang/HJUgNMhs2",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/39xxx/CVE-2023-39363.json",
        "https://github.com/vyperlang/vyper/security/advisories/GHSA-5824-cm3x-3c38",
        "https://nvd.nist.gov/vuln/detail/CVE-2023-39363",
        "https://github.com/vyperlang/vyper/pull/2439",
        "https://github.com/vyperlang/vyper/pull/2514"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-863"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/39xxx/CVE-2023-39363.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2023-39363",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 496601,
  "published_at": "2023-08-07T18:40:25.615+00:00"
}