{"id":"CVE-2023-32058","aliases":["EUVD-2023-0271","GHSA-6r8q-pfpv-7cgj","PYSEC-2023-78"],"status":"published","title":"Vyper vulnerable to integer overflow in loop","description":"Vyper is a Pythonic smart contract language for the Ethereum virtual machine. Prior to version 0.3.8, due to missing overflow check for loop variables, by assigning the iterator of a loop to a variable, it is possible to overflow the type of the latter. The issue seems to happen only in loops of type `for i in range(a, a + N)` as in loops of type `for i in range(start, stop)` and `for i in range(stop)`, the compiler is able to raise a `TypeMismatch` when trying to overflow the variable. The problem has been patched in version 0.3.8.","severity":{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.00913,"percentile":0.60333,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-190"],"published":"2023-05-11T20:55:35Z","modified":"2026-10-28T02:31:00Z","fixes":[{"ecosystem":"PyPI","package":"vyper","fixed_in":["0.3.8"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"PyPI","package":"vyper","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.3.8"}]}]},{"source":"osv","ecosystem":"PyPI","package":"vyper","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.3.8"}]}],"versions":["0.1.0b1","0.1.0b10","0.1.0b11","0.1.0b12","0.1.0b13","0.1.0b14","0.1.0b15","0.1.0b16","0.1.0b17","0.1.0b2","0.1.0b3","0.1.0b4","0.1.0b5","0.1.0b6","0.1.0b7","0.1.0b8","0.1.0b9","0.2.1","0.2.10","0.2.11","0.2.12","0.2.13","0.2.14","0.2.15","0.2.16","0.2.2","0.2.3","0.2.4","0.2.5","0.2.6","0.2.7","0.2.8","0.2.9","0.3.0","0.3.1","0.3.2","0.3.3","0.3.4","0.3.5","0.3.6","0.3.7"]},{"source":"osv","ecosystem":"PyPI","package":"vyper","ranges":[{"type":"GIT","events":[{"introduced":"0"},{"fixed":"3de1415ee77a9244eb04bdb695e249d3ec9ed868"}]},{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.3.8"}]}],"versions":["0.1.0b1","0.1.0b10","0.1.0b11","0.1.0b12","0.1.0b13","0.1.0b14","0.1.0b15","0.1.0b16","0.1.0b17","0.1.0b2","0.1.0b3","0.1.0b4","0.1.0b5","0.1.0b6","0.1.0b7","0.1.0b8","0.1.0b9","0.2.1","0.2.10","0.2.11","0.2.12","0.2.13","0.2.14","0.2.15","0.2.16","0.2.2","0.2.3","0.2.4","0.2.5","0.2.6","0.2.7","0.2.8","0.2.9","0.3.0","0.3.1","0.3.2","0.3.3","0.3.4","0.3.5","0.3.6","0.3.7"]}],"products":[{"vendor":"vyperlang","product":"vyper"}],"references":[{"url":"https://github.com/vyperlang/vyper/security/advisories/GHSA-6r8q-pfpv-7cgj","tags":["x_refsource_CONFIRM","x_transferred","Exploit","Vendor Advisory","advisory","web"]},{"url":"https://github.com/vyperlang/vyper/commit/3de1415ee77a9244eb04bdb695e249d3ec9ed868","tags":["x_refsource_MISC","x_transferred","Patch","fix","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2023-32058","tags":["advisory"]},{"url":"https://github.com/pypa/advisory-database/tree/main/vulns/vyper/PYSEC-2023-78.yaml","tags":["web"]},{"url":"https://github.com/advisories/GHSA-6r8q-pfpv-7cgj"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/32xxx/CVE-2023-32058.json","tags":["advisory"]},{"url":"https://github.com/vyperlang/vyper","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2023-32058","title":"Vyper vulnerable to integer overflow in loop","description":"Vyper is a Pythonic smart contract language for the Ethereum virtual machine. Prior to version 0.3.8, due to missing overflow check for loop variables, by assigning the iterator of a loop to a variable, it is possible to overflow the type of the latter. The issue seems to happen only in loops of type `for i in range(a, a + N)` as in loops of type `for i in range(start, stop)` and `for i in range(stop)`, the compiler is able to raise a `TypeMismatch` when trying to overflow the variable. The problem has been patched in version 0.3.8.","status":"published","published":"2023-05-11T20:55:35.195Z","modified":"2025-01-24T15:57:47.118Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"cna"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"adp"}],"cwes":["CWE-190","CWE-190"],"updated_at":"2026-11-02T14:35:29.01154Z"}],"euvd":[{"id":"EUVD-2023-0271","description":"Vyper is a Pythonic smart contract language for the Ethereum virtual machine. Prior to version 0.3.8, due to missing overflow check for loop variables, by assigning the iterator of a loop to a variable, it is possible to overflow the type of the latter. The issue seems to happen only in loops of type `for i in range(a, a + N)` as in loops of type `for i in range(start, stop)` and `for i in range(stop)`, the compiler is able to raise a `TypeMismatch` when trying to overflow the variable. The problem has been patched in version 0.3.8.","status":"published","published":"2023-05-11T20:55:35Z","modified":"2025-01-24T15:57:47Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-03T00:04:14.026358Z"}],"ghsa":[{"id":"GHSA-6r8q-pfpv-7cgj","title":"Vyper vulnerable to integer overflow in loop","description":"### Impact\n\nDue to missing overflow check for loop variables, by assigning the iterator of a loop to a variable, it is possible to overflow the type of the latter.\n\nIn the following example, calling `test` returns `354`, meaning that the variable `a` did store `354` a value out of bound for the type `uint8`.\n\n```Vyper\n@external\ndef test() -\u003e uint16:\n    x:uint8 = 255\n    a:uint8 = 0\n    for i in range(x, x+100):\n        a = i\n    return convert(a,uint16)\n```\n\nThe issue seems to happen only in loops of type `for i in range(a, a + N)` as in loops of type `for i in range(start, stop)` and `for i in range(stop)`, the compiler is able to raise a `TypeMismatch` when trying to overflow the variable.\n\nthanks to @trocher for reporting\n\n### Patches\n\npatched in 3de1415ee77a9244eb04bdb695e249d3ec9ed868\n\n### Workarounds\n\n ","status":"published","published":"2023-05-12T20:21:35Z","modified":"2024-11-19T16:32:39Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"},{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","level":"high"}],"cwes":["CWE-190"],"updated_at":"2026-11-02T14:38:21.777721Z"}],"nvd":[{"id":"CVE-2023-32058","description":"Vyper is a Pythonic smart contract language for the Ethereum virtual machine. Prior to version 0.3.8, due to missing overflow check for loop variables, by assigning the iterator of a loop to a variable, it is possible to overflow the type of the latter. The issue seems to happen only in loops of type `for i in range(a, a + N)` as in loops of type `for i in range(start, stop)` and `for i in range(stop)`, the compiler is able to raise a `TypeMismatch` when trying to overflow the variable. The problem has been patched in version 0.3.8.","status":"published","published":"2023-05-11T21:15:10.397Z","modified":"2026-06-17T05:57:59.007Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"secondary"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"primary"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"secondary"}],"cwes":["CWE-190"],"updated_at":"2026-11-02T14:08:02.399327Z"}],"osv":[{"id":"CVE-2023-32058","title":"Vyper vulnerable to integer overflow in loop","description":"Vyper is a Pythonic smart contract language for the Ethereum virtual machine. Prior to version 0.3.8, due to missing overflow check for loop variables, by assigning the iterator of a loop to a variable, it is possible to overflow the type of the latter. The issue seems to happen only in loops of type `for i in range(a, a + N)` as in loops of type `for i in range(start, stop)` and `for i in range(stop)`, the compiler is able to raise a `TypeMismatch` when trying to overflow the variable. The problem has been patched in version 0.3.8.","status":"published","published":"2023-05-11T20:55:35.195Z","modified":"2026-10-28T02:31:00.448239504Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"cwes":["CWE-190"],"updated_at":"2026-11-02T15:44:31.790231Z"},{"id":"GHSA-6r8q-pfpv-7cgj","title":"Vyper vulnerable to integer overflow in loop","description":"### Impact\n\nDue to missing overflow check for loop variables, by assigning the iterator of a loop to a variable, it is possible to overflow the type of the latter.\n\nIn the following example, calling `test` returns `354`, meaning that the variable `a` did store `354` a value out of bound for the type `uint8`.\n\n```Vyper\n@external\ndef test() -\u003e uint16:\n    x:uint8 = 255\n    a:uint8 = 0\n    for i in range(x, x+100):\n        a = i\n    return convert(a,uint16)\n```\n\nThe issue seems to happen only in loops of type `for i in range(a, a + N)` as in loops of type `for i in range(start, stop)` and `for i in range(stop)`, the compiler is able to raise a `TypeMismatch` when trying to overflow the variable.\n\nthanks to @trocher for reporting\n\n### Patches\n\npatched in 3de1415ee77a9244eb04bdb695e249d3ec9ed868\n\n### Workarounds\n\n ","status":"published","published":"2023-05-12T20:21:35Z","modified":"2026-09-10T03:50:01.254556464Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"},{"version":"4.0","score":8.7,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","level":"high"}],"cwes":["CWE-190"],"updated_at":"2026-11-02T15:46:39.965326Z"},{"id":"PYSEC-2023-78","description":"Vyper is a Pythonic smart contract language for the Ethereum virtual machine. Prior to version 0.3.8, due to missing overflow check for loop variables, by assigning the iterator of a loop to a variable, it is possible to overflow the type of the latter. The issue seems to happen only in loops of type `for i in range(a, a + N)` as in loops of type `for i in range(start, stop)` and `for i in range(stop)`, the compiler is able to raise a `TypeMismatch` when trying to overflow the variable. The problem has been patched in version 0.3.8.","status":"published","published":"2023-05-11T21:15:00Z","modified":"2023-11-08T04:12:32.82478Z","updated_at":"2026-11-02T15:52:53.837392Z"}]}}