{"cve":"CVE-2021-23543","nvd":{"published":"2022-01-10T14:10:16.963","modified":"2026-06-17T03:38:49.113","status":"Modified","description":"All versions of package realms-shim are vulnerable to Sandbox Bypass via a Prototype Pollution attack vector.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","score":9.8},"cwes":["CWE-1321"],"references":["https://snyk.io/vuln/SNYK-JS-REALMSSHIM-2309908","https://www.npmjs.com/package/realms-shim","https://snyk.io/vuln/SNYK-JS-REALMSSHIM-2309908","https://www.npmjs.com/package/realms-shim"],"products":["agoric:realms-shim"],"source":"nvd","synced_at":"2026-10-19T21:26:33.761856376+00:00"},"epss":{"cve":"CVE-2021-23543","score":0.0182,"percentile":0.78748,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-q4j7-v27r-fgcx","url":"https://osv.dev/vulnerability/GHSA-q4j7-v27r-fgcx","summary":"Prototype Pollution in realms-shim","modified":"2026-03-13T21:57:01.858728Z","packages":[{"ecosystem":"npm","name":"realms-shim","purl":"pkg:npm/realms-shim","ranges":["<=1.2.2"],"fixed":[]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}