{"id":"CVE-2021-20088","url":"https://www.cyber-defence.io/tools/cve/CVE-2021-20088","generatedAt":"2026-10-27T23:43:25.562Z","title":"Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution') in mootools-more 1.6.0 allows a malicious user to inject properties into Object.prototype.","description":"Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution') in mootools-more 1.6.0 allows a malicious user to inject properties into Object.prototype.","published":"2021-04-23T18:15:08.000Z","lastModified":"2026-06-17T03:33:15.000Z","status":"Modified","sourceIdentifier":"vulnreport@tenable.com","cvss":{"version":"3.1","score":8.8,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"},"cwe":["CWE-1321"],"affected":["mootools/mootools-more"],"epss":{"score":0.01449,"percentile":0.73173,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (1.45%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://github.com/BlackFan/client-side-prototype-pollution/blob/master/pp/mootools-more.md","tags":["Exploit","Third Party Advisory"],"source":"vulnreport@tenable.com"},{"url":"https://github.com/BlackFan/client-side-prototype-pollution/blob/master/pp/mootools-more.md","tags":["Exploit","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-20088","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}