{"id":"CVE-2021-26505","aliases":["GHSA-g3vf-47fv-8f3c"],"url":"https://o3.security/vulnerability/CVE-2021-26505","summary":"MrSwitch hello.js vulnerable to prototype pollution","details":"A prototype pollution vulnerability in MrSwitch hello.js prior to version 1.18.8 allows remote attackers to execute arbitrary code via `hello.utils.extend` function.","published":"2023-08-11T14:15:12.257Z","modified":"2026-07-08T21:26:15.185826Z","cvss":{"score":9.8,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"npm","name":"hellojs","fixedVersion":"1.18.8"}],"fix":{"url":"https://github.com/MrSwitch/hello.js/commit/7ab50aeff2d41991f08d4ad6c0481125eea8f6b7","label":"MrSwitch/hello.js@7ab50ae"},"references":[{"type":"REPORT","url":"https://github.com/MrSwitch/hello.js/issues/634"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2021-26505"},{"type":"WEB","url":"https://github.com/MrSwitch/hello.js/commit/7ab50aeff2d41991f08d4ad6c0481125eea8f6b7"},{"type":"PACKAGE","url":"https://github.com/MrSwitch/hello.js"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-07-08T21:26:15.185826Z"}}