{"schemaVersion":3,"id":"USN-4756-1","aliases":[],"status":"published","duplicateOf":null,"title":null,"description":"firefox vulnerabilities\n\nMultiple security issues were discovered in Firefox. If a user were\ntricked into opening a specially crafted website, an attacker could\npotentially exploit these to cause a denial of service, obtain sensitive\ninformation, conduct cross-site scripting (XSS) attacks, bypass HTTP auth\nphishing warnings, or execute arbitrary code.","dates":{"published":"2021-02-26T18:11:10.000Z","modified":"2026-04-22T10:11:56.813Z","reserved":null,"kevAdded":[],"kevDue":[]},"cvss":{"headline":{"score":null,"severity":"unknown","version":null,"versionLabel":null,"source":null,"vector":null,"computed":false,"selection":"none"},"metrics":[]},"epss":{"probability":null,"percentile":null,"severity":"unknown","asOf":null,"change":{"pp":null,"baselineDate":null,"baselineScore":null},"history":[],"last30":[]},"kev":{"state":"not-listed","entries":[],"listedCount":0,"totalCatalogs":3,"catalogs":[{"source":"cisa","label":"CISA","listed":false,"entry":null},{"source":"enisa","label":"ENISA","listed":false,"entry":null},{"source":"circl","label":"CIRCL","listed":false,"entry":null}]},"ransomware":{"state":"none-recorded","sources":[]},"exploits":[],"exploitCount":0,"weaknesses":[],"affected":[{"vendor":"ubuntu","product":"firefox","name":"firefox","label":"firefox","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/firefox","purlType":"deb","versions":[{"text":"< 86.0+build3-0ubuntu0.16.04.1","noFixRecorded":false,"fixedIn":null},{"text":"< 86.0+build3-0ubuntu0.18.04.1","noFixRecorded":false,"fixedIn":null},{"text":"< 86.0+build3-0ubuntu0.20.04.1","noFixRecorded":false,"fixedIn":null}],"versionsText":"< 86.0+build3-0ubuntu0.16.04.1 | < 86.0+build3-0ubuntu0.18.04.1 | < 86.0+build3-0ubuntu0.20.04.1","eol":null,"hubHref":null}],"affectedCount":1,"eol":{"hasEol":false,"count":0},"references":[{"url":"https://ubuntu.com/security/notices/USN-4756-1","label":"ubuntu.com/security/notices/USN-4756-1","hostname":"ubuntu.com","tags":["Advisory"]},{"url":"https://ubuntu.com/security/CVE-2021-23968","label":"ubuntu.com/security/CVE-2021-23968","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://ubuntu.com/security/CVE-2021-23969","label":"ubuntu.com/security/CVE-2021-23969","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://ubuntu.com/security/CVE-2021-23970","label":"ubuntu.com/security/CVE-2021-23970","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://ubuntu.com/security/CVE-2021-23971","label":"ubuntu.com/security/CVE-2021-23971","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://ubuntu.com/security/CVE-2021-23972","label":"ubuntu.com/security/CVE-2021-23972","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://ubuntu.com/security/CVE-2021-23973","label":"ubuntu.com/security/CVE-2021-23973","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://ubuntu.com/security/CVE-2021-23974","label":"ubuntu.com/security/CVE-2021-23974","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://ubuntu.com/security/CVE-2021-23975","label":"ubuntu.com/security/CVE-2021-23975","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://ubuntu.com/security/CVE-2021-23978","label":"ubuntu.com/security/CVE-2021-23978","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://ubuntu.com/security/CVE-2021-23979","label":"ubuntu.com/security/CVE-2021-23979","hostname":"ubuntu.com","tags":["REPORT"]}],"lineage":{"upstream":["CVE-2021-23968","CVE-2021-23969","CVE-2021-23970","CVE-2021-23971","CVE-2021-23972","CVE-2021-23973","CVE-2021-23974","CVE-2021-23975","CVE-2021-23978","CVE-2021-23979"],"downstream":[],"duplicates":[],"related":["CVE-2021-23968","CVE-2021-23969","CVE-2021-23970","CVE-2021-23971","CVE-2021-23972","CVE-2021-23973","CVE-2021-23974","CVE-2021-23975","CVE-2021-23978","CVE-2021-23979"]},"timeline":[{"kind":"published","date":"2021-02-26T18:11:10.000Z","label":"Published","detail":"Vulnerability first disclosed.","source":null},{"kind":"modified","date":"2026-04-22T10:11:56.813Z","label":"Last modified","detail":"Vulnerability information updated.","source":null}],"risk":{"score":0,"level":"minimal","profile":"Default","thresholds":{"critical":75,"high":50,"medium":25,"low":10}},"meta":{"dataAsOf":"2026-10-20T18:45:05.606Z","stale":false,"partial":false}}