{"id":"CVE-2024-32481","aliases":["EUVD-2024-1269","GHSA-ppx5-q359-pvwj","PYSEC-2024-246"],"status":"published","title":"vyper's range(start, start + N) reverts for negative numbers","description":"Vyper is a pythonic Smart Contract Language for the Ethereum virtual machine. Starting in version 0.3.8 and prior to version 0.4.0b1, when looping over a `range` of the form `range(start, start + N)`, if `start` is negative, the execution will always revert. This issue is caused by an incorrect assertion inserted by the code generation of the range `stmt.parse_For_range()`. The issue arises when `start` is signed, instead of using `sle`, `le` is used and `start` is interpreted as an unsigned integer for the comparison. If it is a negative number, its 255th bit is set to `1` and is hence interpreted as a very large unsigned integer making the assertion always fail. Any contract having a `range(start, start + N)` where `start` is a signed integer with the possibility for `start` to be negative is affected. If a call goes through the loop while supplying a negative `start` the execution will revert. Version 0.4.0b1 fixes the issue.","severity":{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.00791,"percentile":0.56746,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-681"],"published":"2024-04-25T17:00:54Z","modified":"2026-10-28T02:31:08Z","fixes":[{"ecosystem":"PyPI","package":"vyper","fixed_in":["0.4.0","0.4.0b1"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"PyPI","package":"vyper","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0.3.8"},{"fixed":"0.4.0"}]}]},{"source":"osv","ecosystem":"PyPI","package":"vyper","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0.3.8"},{"fixed":"0.4.0"}]}],"versions":["0.3.10","0.3.10rc1","0.3.10rc2","0.3.10rc3","0.3.10rc4","0.3.10rc5","0.3.8","0.3.9","0.4.0b1","0.4.0b2","0.4.0b3","0.4.0b4","0.4.0b5","0.4.0b6","0.4.0rc1","0.4.0rc2","0.4.0rc3","0.4.0rc4","0.4.0rc5","0.4.0rc6"]},{"source":"osv","ecosystem":"PyPI","package":"vyper","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0.3.8"},{"fixed":"0.4.0b1"}]}],"versions":["0.3.10","0.3.10rc1","0.3.10rc2","0.3.10rc3","0.3.10rc4","0.3.10rc5","0.3.8","0.3.9"]}],"products":[{"vendor":"vyperlang","product":"vyper"}],"references":[{"url":"https://github.com/vyperlang/vyper/security/advisories/GHSA-ppx5-q359-pvwj","tags":["x_refsource_CONFIRM","x_transferred","Exploit","Vendor Advisory","advisory","web","evidence"]},{"url":"https://github.com/vyperlang/vyper/commit/3de1415ee77a9244eb04bdb695e249d3ec9ed868","tags":["x_refsource_MISC","x_transferred","Patch","fix","web"]},{"url":"https://github.com/vyperlang/vyper/commit/5319cfbe14951e007ccdb323257e5ada869b35d5","tags":["x_refsource_MISC","x_transferred","Patch","fix","web"]},{"url":"https://github.com/vyperlang/vyper/blob/9136169468f317a53b4e7448389aa315f90b95ba/vyper/codegen/stmt.py#L286-L287","tags":["x_refsource_MISC","x_transferred","Product","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2024-32481","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-ppx5-q359-pvwj","tags":["advisory"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/32xxx/CVE-2024-32481.json","tags":["advisory"]},{"url":"https://github.com/vyperlang/vyper","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2024-32481","title":"vyper's range(start, start + N) reverts for negative numbers","description":"Vyper is a pythonic Smart Contract Language for the Ethereum virtual machine. Starting in version 0.3.8 and prior to version 0.4.0b1, when looping over a `range` of the form `range(start, start + N)`, if `start` is negative, the execution will always revert. This issue is caused by an incorrect assertion inserted by the code generation of the range `stmt.parse_For_range()`. The issue arises when `start` is signed, instead of using `sle`, `le` is used and `start` is interpreted as an unsigned integer for the comparison. If it is a negative number, its 255th bit is set to `1` and is hence interpreted as a very large unsigned integer making the assertion always fail. Any contract having a `range(start, start + N)` where `start` is a signed integer with the possibility for `start` to be negative is affected. If a call goes through the loop while supplying a negative `start` the execution will revert. Version 0.4.0b1 fixes the issue.","status":"published","published":"2024-04-25T17:00:54.082Z","modified":"2024-08-02T02:13:39.3Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","level":"medium","assessor":"cna"}],"cwes":["CWE-681"],"updated_at":"2026-11-02T14:34:15.662528Z"}],"euvd":[{"id":"EUVD-2024-1269","description":"Vyper is a pythonic Smart Contract Language for the Ethereum virtual machine. Starting in version 0.3.8 and prior to version 0.4.0b1, when looping over a `range` of the form `range(start, start + N)`, if `start` is negative, the execution will always revert. This issue is caused by an incorrect assertion inserted by the code generation of the range `stmt.parse_For_range()`. The issue arises when `start` is signed, instead of using `sle`, `le` is used and `start` is interpreted as an unsigned integer for the comparison. If it is a negative number, its 255th bit is set to `1` and is hence interpreted as a very large unsigned integer making the assertion always fail. Any contract having a `range(start, start + N)` where `start` is a signed integer with the possibility for `start` to be negative is affected. If a call goes through the loop while supplying a negative `start` the execution will revert. Version 0.4.0b1 fixes the issue.","status":"published","published":"2024-04-25T17:00:54Z","modified":"2024-08-02T02:13:39Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","level":"medium"}],"updated_at":"2026-11-03T03:50:23.057649Z"}],"ghsa":[{"id":"GHSA-ppx5-q359-pvwj","title":"vyper's range(start, start + N) reverts for negative numbers","description":"### Summary\n\nWhen looping over a `range` of the form `range(start, start + N)`, if `start` is negative, the execution will always revert.\n \n### Details\n\nThis issue is caused by an incorrect assertion inserted by the code generation of the range (`stmt.parse_For_range()`):\n\nhttps://github.com/vyperlang/vyper/blob/9136169468f317a53b4e7448389aa315f90b95ba/vyper/codegen/stmt.py#L286-L287\n\nThis assertion was introduced in https://github.com/vyperlang/vyper/commit/3de1415ee77a9244eb04bdb695e249d3ec9ed868 to fix https://github.com/advisories/GHSA-6r8q-pfpv-7cgj. The issue arises when `start` is signed, instead of using `sle`, `le` is used and `start` is interpreted as an unsigned integer for the comparison. If it is a negative number, its 255th bit is set to `1` and is hence interpreted as a very large unsigned integer making the assertion always fail. \n### PoC\n\n```Vyper\n@external\ndef foo():\n    x:int256 = min_value(int256)\n    # revert when it should not since we have the following assertion that fails:\n    # [assert, [le, min_value(int256), max_value(int256) + 1 - 10]],\n    for i in range(x, x + 10):\n        pass\n```\n\n### Patches\n\npatched in v0.4.0, specifically, https://github.com/vyperlang/vyper/pull/3679 disallows this form of `range()`.\n\n### Impact\n\nAny contract having a `range(start, start + N)` where `start` is a signed integer with the possibility for `start` to be negative is affected. If a call goes through the loop while supplying a negative `start` the execution will revert.","status":"published","published":"2024-04-25T19:53:43Z","modified":"2024-04-25T19:53:45Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","level":"medium"}],"cwes":["CWE-681"],"updated_at":"2026-11-02T14:37:46.667202Z"}],"nvd":[{"id":"CVE-2024-32481","description":"Vyper is a pythonic Smart Contract Language for the Ethereum virtual machine. Starting in version 0.3.8 and prior to version 0.4.0b1, when looping over a `range` of the form `range(start, start + N)`, if `start` is negative, the execution will always revert. This issue is caused by an incorrect assertion inserted by the code generation of the range `stmt.parse_For_range()`. The issue arises when `start` is signed, instead of using `sle`, `le` is used and `start` is interpreted as an unsigned integer for the comparison. If it is a negative number, its 255th bit is set to `1` and is hence interpreted as a very large unsigned integer making the assertion always fail. Any contract having a `range(start, start + N)` where `start` is a signed integer with the possibility for `start` to be negative is affected. If a call goes through the loop while supplying a negative `start` the execution will revert. Version 0.4.0b1 fixes the issue.","status":"published","published":"2024-04-25T17:15:50.273Z","modified":"2026-06-17T07:29:42.71Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","level":"medium","assessor":"secondary"},{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","level":"medium","assessor":"primary"}],"cwes":["CWE-681"],"updated_at":"2026-11-02T14:09:53.50104Z"}],"osv":[{"id":"CVE-2024-32481","title":"vyper's range(start, start + N) reverts for negative numbers","description":"Vyper is a pythonic Smart Contract Language for the Ethereum virtual machine. Starting in version 0.3.8 and prior to version 0.4.0b1, when looping over a `range` of the form `range(start, start + N)`, if `start` is negative, the execution will always revert. This issue is caused by an incorrect assertion inserted by the code generation of the range `stmt.parse_For_range()`. The issue arises when `start` is signed, instead of using `sle`, `le` is used and `start` is interpreted as an unsigned integer for the comparison. If it is a negative number, its 255th bit is set to `1` and is hence interpreted as a very large unsigned integer making the assertion always fail. Any contract having a `range(start, start + N)` where `start` is a signed integer with the possibility for `start` to be negative is affected. If a call goes through the loop while supplying a negative `start` the execution will revert. Version 0.4.0b1 fixes the issue.","status":"published","published":"2024-04-25T17:00:54.082Z","modified":"2026-10-28T02:31:08.471757574Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","level":"medium"}],"cwes":["CWE-681"],"updated_at":"2026-11-02T15:44:40.391953Z"},{"id":"GHSA-ppx5-q359-pvwj","title":"vyper's range(start, start + N) reverts for negative numbers","description":"### Summary\n\nWhen looping over a `range` of the form `range(start, start + N)`, if `start` is negative, the execution will always revert.\n \n### Details\n\nThis issue is caused by an incorrect assertion inserted by the code generation of the range (`stmt.parse_For_range()`):\n\nhttps://github.com/vyperlang/vyper/blob/9136169468f317a53b4e7448389aa315f90b95ba/vyper/codegen/stmt.py#L286-L287\n\nThis assertion was introduced in https://github.com/vyperlang/vyper/commit/3de1415ee77a9244eb04bdb695e249d3ec9ed868 to fix https://github.com/advisories/GHSA-6r8q-pfpv-7cgj. The issue arises when `start` is signed, instead of using `sle`, `le` is used and `start` is interpreted as an unsigned integer for the comparison. If it is a negative number, its 255th bit is set to `1` and is hence interpreted as a very large unsigned integer making the assertion always fail. \n### PoC\n\n```Vyper\n@external\ndef foo():\n    x:int256 = min_value(int256)\n    # revert when it should not since we have the following assertion that fails:\n    # [assert, [le, min_value(int256), max_value(int256) + 1 - 10]],\n    for i in range(x, x + 10):\n        pass\n```\n\n### Patches\n\npatched in v0.4.0, specifically, https://github.com/vyperlang/vyper/pull/3679 disallows this form of `range()`.\n\n### Impact\n\nAny contract having a `range(start, start + N)` where `start` is a signed integer with the possibility for `start` to be negative is affected. If a call goes through the loop while supplying a negative `start` the execution will revert.","status":"published","published":"2024-04-25T19:53:43Z","modified":"2026-06-10T17:14:19.549169376Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","level":"medium"}],"cwes":["CWE-681"],"updated_at":"2026-11-02T15:46:53.244788Z"},{"id":"PYSEC-2024-246","description":"Vyper is a pythonic Smart Contract Language for the Ethereum virtual machine. Starting in version 0.3.8 and prior to version 0.4.0b1, when looping over a `range` of the form `range(start, start + N)`, if `start` is negative, the execution will always revert. This issue is caused by an incorrect assertion inserted by the code generation of the range `stmt.parse_For_range()`. The issue arises when `start` is signed, instead of using `sle`, `le` is used and `start` is interpreted as an unsigned integer for the comparison. If it is a negative number, its 255th bit is set to `1` and is hence interpreted as a very large unsigned integer making the assertion always fail. Any contract having a `range(start, start + N)` where `start` is a signed integer with the possibility for `start` to be negative is affected. If a call goes through the loop while supplying a negative `start` the execution will revert. Version 0.4.0b1 fixes the issue.","status":"published","published":"2024-04-25T17:15:50Z","modified":"2026-06-10T17:14:16.630944247Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","level":"medium"}],"updated_at":"2026-11-02T15:52:54.242332Z"}]}}