{"id":"CVE-2021-48020","aliases":["EUVD-2021-34890","GHSA-22wc-c9wj-6q2v","GHSA-vq78-2j7f-9gqx"],"status":"published","title":"Vyper before 0.3.0 Memory Corruption via Internal Function Calls in Arrays","description":"Vyper from 0.1.0b4 before 0.3.0 contains a memory corruption vulnerability caused by an incorrect stack tip pointer when internal function calls are performed inside arrays. Contracts placing internal calls in nested array elements, external call arguments, struct literals, or raw_log topics can have memory corrupted, producing incorrect contract behavior.","severity":{"version":"4.0","score":8.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.00284,"percentile":0.21171,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-129","CWE-787"],"published":"2021-04-19T15:12:05Z","modified":"2026-10-30T02:45:09Z","fixes":[{"ecosystem":"PyPI","package":"vyper","fixed_in":["0.2.12"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"PyPI","package":"vyper","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.2.12"}]}]},{"source":"osv","ecosystem":"PyPI","package":"vyper","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.2.12"}]}],"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","0.2.2","0.2.3","0.2.4","0.2.5","0.2.6","0.2.7","0.2.8","0.2.9"]}],"products":[{"vendor":"vyperlang","product":"vyper"}],"references":[{"url":"https://github.com/vyperlang/vyper/security/advisories/GHSA-22wc-c9wj-6q2v","tags":["vendor-advisory","advisory","web"]},{"url":"https://www.vulncheck.com/advisories/vyper-before-0.3.0-memory-corruption-via-internal-function-calls-in-arrays","tags":["third-party-advisory","advisory"]},{"url":"https://github.com/vyperlang/vyper/pull/2345","tags":["web"]},{"url":"https://github.com/vyperlang/vyper/commit/11b7b5b7e59bc9dc859d51cd41a924b59fe47c9e","tags":["web"]},{"url":"https://pypi.org/project/vyper","tags":["web"]},{"url":"https://github.com/advisories/GHSA-22wc-c9wj-6q2v"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-48020"},{"url":"https://github.com/advisories/GHSA-vq78-2j7f-9gqx"}],"sources":{"cve":[{"id":"CVE-2021-48020","title":"Vyper before 0.3.0 Memory Corruption via Internal Function Calls in Arrays","description":"Vyper from 0.1.0b4 before 0.3.0 contains a memory corruption vulnerability caused by an incorrect stack tip pointer when internal function calls are performed inside arrays. Contracts placing internal calls in nested array elements, external call arguments, struct literals, or raw_log topics can have memory corrupted, producing incorrect contract behavior.","status":"published","published":"2026-10-21T00:36:19.625Z","modified":"2026-10-28T15:11:17.839Z","cvss":[{"version":"4.0","score":8.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N","level":"high","assessor":"cna"},{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:L","level":"medium","assessor":"cna"}],"cwes":["CWE-787"],"updated_at":"2026-11-02T14:33:04.360272Z"}],"euvd":[{"id":"EUVD-2021-34890","description":"Vyper from 0.1.0b4 before 0.3.0 contains a memory corruption vulnerability caused by an incorrect stack tip pointer when internal function calls are performed inside arrays. Contracts placing internal calls in nested array elements, external call arguments, struct literals, or raw_log topics can have memory corrupted, producing incorrect contract behavior.","status":"published","published":"2026-10-21T00:36:19Z","modified":"2026-10-28T15:11:17Z","cvss":[{"version":"4.0","score":8.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N","level":"high"}],"updated_at":"2026-11-02T16:59:20.750321Z"}],"ghsa":[{"id":"GHSA-vq78-2j7f-9gqx","title":"Vyper from 0.1.0b4 before 0.3.0 contains a memory corruption vulnerability caused by an incorrect...","description":"Vyper from 0.1.0b4 before 0.3.0 contains a memory corruption vulnerability caused by an incorrect stack tip pointer when internal function calls are performed inside arrays. Contracts placing internal calls in nested array elements, external call arguments, struct literals, or raw_log topics can have memory corrupted, producing incorrect contract behavior.","status":"published","published":"2026-10-21T03:32:11Z","modified":"2026-10-21T03:32:16Z","cvss":[{"version":"4.0","score":8.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high"},{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:L","level":"medium"}],"cwes":["CWE-787"],"updated_at":"2026-11-02T15:14:08.480034Z"},{"id":"GHSA-22wc-c9wj-6q2v","title":"VVE-2021-0001: Memory corruption using function calls within arrays","description":"### Impact\nWhen performing a function call inside an array, there is a memory corruption issue that occurs because of an incorrect pointer to the the tip of the stack.\n\n### Patches\nThis issue was partially fixed in [VVE-2020-0004](https://github.com/vyperlang/vyper/security/advisories/GHSA-2r3x-4mrv-mcxf), however the fix did not update similar code for arrays, which had a similar issue. The issue is fully fixed in https://github.com/vyperlang/vyper/pull/2345","status":"published","published":"2021-04-19T15:12:05Z","modified":"2023-01-09T05:04:55Z","cwes":["CWE-129"],"updated_at":"2026-11-02T14:36:10.502376Z"}],"nvd":[{"id":"CVE-2021-48020","description":"Vyper from 0.1.0b4 before 0.3.0 contains a memory corruption vulnerability caused by an incorrect stack tip pointer when internal function calls are performed inside arrays. Contracts placing internal calls in nested array elements, external call arguments, struct literals, or raw_log topics can have memory corrupted, producing incorrect contract behavior.","status":"published","published":"2026-10-21T01:17:19.3Z","modified":"2026-10-28T16:16:59.973Z","cvss":[{"version":"4.0","score":8.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high","assessor":"secondary"},{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:L","level":"medium","assessor":"secondary"}],"cwes":["CWE-787"],"updated_at":"2026-11-02T14:07:09.005706Z"}],"osv":[{"id":"CVE-2021-48020","description":"Vyper from 0.1.0b4 before 0.3.0 contains a memory corruption vulnerability caused by an incorrect stack tip pointer when internal function calls are performed inside arrays. Contracts placing internal calls in nested array elements, external call arguments, struct literals, or raw_log topics can have memory corrupted, producing incorrect contract behavior.","status":"published","published":"2026-10-21T01:17:19.3Z","modified":"2026-10-30T02:45:09.009703529Z","cvss":[{"version":"4.0","score":8.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high"}],"updated_at":"2026-11-02T15:44:22.824781Z"},{"id":"GHSA-22wc-c9wj-6q2v","title":"VVE-2021-0001: Memory corruption using function calls within arrays","description":"### Impact\nWhen performing a function call inside an array, there is a memory corruption issue that occurs because of an incorrect pointer to the the tip of the stack.\n\n### Patches\nThis issue was partially fixed in [VVE-2020-0004](https://github.com/vyperlang/vyper/security/advisories/GHSA-2r3x-4mrv-mcxf), however the fix did not update similar code for arrays, which had a similar issue. The issue is fully fixed in https://github.com/vyperlang/vyper/pull/2345","status":"published","published":"2021-04-19T15:12:05Z","modified":"2026-10-24T02:56:12.31591223Z","cwes":["CWE-129"],"updated_at":"2026-11-02T15:46:33.520522Z"}]}}