{“lastseen”:””,”description”:”Memory safety bugs present in Firefox ESR 115.33, Firefox ESR 140.8, Thunderbird ESR 140.8, Firefox 148 and Thunderbird 148. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox \\u003c 149, Firefox ESR \\u003c 115.34, Firefox ESR \\u003c 140.9, Thunderbird \\u003c 149, and Thunderbird \\u003c 140.9.”,”published”:”2026-03-24T12:30:44.312Z”,”modified”:”2026-03-25T13:09:23.842Z”,”type”:”cve”,”title”:”Memory safety bugs fixed in Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird ESR 140.9, Firefox 149 and Thunderbird 149″,”source”:”mozilla”,”references”:”https:\/\/bugzilla.mozilla.org\/buglist.cgi?bug_id=2013762%2C2015291%2C2016591%2C2016661%2C2016664%2C2017303%2C2017894%2C2018090%2C2018196%2C2018379%2C2019112%2C2022090%2C2022243%2C2022351%2C2022478%2C2022676\\nhttps:\/\/www.mozilla.org\/security\/advisories\/mfsa2026-20\/\\nhttps:\/\/www.mozilla.org\/security\/advisories\/mfsa2026-21\/\\nhttps:\/\/www.mozilla.org\/security\/advisories\/mfsa2026-22\/\\nhttps:\/\/www.mozilla.org\/security\/advisories\/mfsa2026-23\/\\nhttps:\/\/www.mozilla.org\/security\/advisories\/mfsa2026-24\/”,”id”:”CVE-2026-4721″,”bulletinFamily”:””,”cwe”:[“CWE-120″],”cvelist”:null,”sourceData”:”Mozilla Firefox unspecified\\nMozilla Firefox ESR unspecified\\nMozilla Firefox ESR unspecified\\nMozilla Thunderbird unspecified\\nMozilla Thunderbird unspecified”,”sourceHref”:””,”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”,”version”:”3.1″},”cvss2″:{},”cvss3″:{“version”:””,”vectorString”:””,”baseScore”:0,”baseSeverity”:””,”attackVector”:””,”attackComplexity”:””,”privilegesRequired”:””,”userInteraction”:””,”scope”:””,”confidentialityImpact”:””,”integrityImpact”:””,”availabilityImpact”:””,”cvssV3″:{“version”:””,”vectorString”:””,”baseScore”:0,”baseSeverity”:””,”attackVector”:””,”attackComplexity”:””,”privilegesRequired”:””,”userInteraction”:””,”scope”:””,”confidentialityImpact”:””,”integrityImpact”:””,”availabilityImpact”:””}},”href”:””,”category_name”:”CVE”,”post_link”:””,”product”:”Firefox”,”version”:”unspecified”,”vendor”:”Mozilla”,”ai_description”:””,”ai_severity”:””,”ai_vendor”:””,”ai_product”:””,”ai_version”:””,”ai_score”:0}<\/p>\n","protected":false},"excerpt":{"rendered":"
{“lastseen”:””,”description”:”Memory safety bugs present in Firefox ESR 115.33, Firefox ESR 140.8, Thunderbird ESR 140.8, Firefox 148 and Thunderbird 148. Some of these bugs showed evidence…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2],"tags":[9,6,8,35,12,13,7,11,5],"class_list":["post-46030","post","type-post","status-publish","format-standard","hentry","category-category_cve","tag-critical","tag-cve","tag-cvss","tag-cvss-98","tag-exploit","tag-news","tag-security","tag-tapic","tag-vulnerability"],"yoast_head":"\n