{"id":"CVE-2021-23543","aliases":[],"url":"https://o3.security/vulnerability/CVE-2021-23543","summary":"Prototype Pollution in realms-shim","details":"All versions of package realms-shim are vulnerable to Sandbox Bypass via a Prototype Pollution attack vector.","published":"2022-01-13T15:00:36Z","modified":"2026-03-13T21:57:01.858728Z","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":1,"affectedPackages":[{"ecosystem":"npm","name":"realms-shim","fixedVersion":null}],"fix":null,"references":[{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2021-23543"},{"type":"PACKAGE","url":"https://github.com/Agoric/realms-shim"},{"type":"WEB","url":"https://snyk.io/vuln/SNYK-JS-REALMSSHIM-2309908"},{"type":"WEB","url":"https://www.npmjs.com/package/realms-shim"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-03-13T21:57:01.858728Z"}}