{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "versions": [
              {
                "introduced": "0"
              },
              {
                "last_affected": "0.4.2rc1"
              }
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "11522b836bd0d86cf43ec186aa3b2b8e986ca4fe"
            }
          ],
          "repo": "https://github.com/vyperlang/vyper",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-3vcg-j39x-cwfm"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-691"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/47xxx/CVE-2025-47774.json"
  },
  "details": "Vyper is the Pythonic Programming Language for the Ethereum Virtual Machine. In versions up to and including 0.4.2rc1, the `slice()` builtin can elide side effects when the output length is 0, and the source bytestring is a builtin (`msg.data` or `\u003caddress\u003e.code`). The reason is that for these source locations, the check that `length \u003e= 1` is skipped. The result is that a 0-length bytestring constructed with slice can be passed to `make_byte_array_copier`, which elides evaluation of its source argument when the max length is 0. The impact is that side effects in the `start` argument may be elided when the `length` argument is 0, e.g. `slice(msg.data, self.do_side_effect(), 0)`. The fix in pull request 4645 disallows any invocation of `slice()` with length 0, including for the ad hoc locations discussed in this advisory. The fix is expected to be part of version 0.4.2.",
  "id": "CVE-2025-47774",
  "modified": "2026-04-01T23:10:34.959218027Z",
  "published": "2025-05-15T17:38:58.487Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/vyperlang/vyper/blob/68b68c4b30c5ef2f312b4674676170b8a6eaa316/vyper/builtins/functions.py#L315-L319"
    },
    {
      "type": "WEB",
      "url": "https://github.com/vyperlang/vyper/blob/68b68c4b30c5ef2f312b4674676170b8a6eaa316/vyper/codegen/core.py#L189-L191"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/47xxx/CVE-2025-47774.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/vyperlang/vyper/security/advisories/GHSA-3vcg-j39x-cwfm"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-47774"
    },
    {
      "type": "FIX",
      "url": "https://github.com/vyperlang/vyper/pull/4645"
    }
  ],
  "schema_version": "1.7.3",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Vyper's `slice()` may elide side-effects when output length is 0"
}