{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata. Fed continuously.","feed_url":"https://feed.craftedsignal.io/tags/cve-2026-4711/feed.json","home_page_url":"https://feed.craftedsignal.io/","items":[{"_cs_actors":[],"_cs_cpes":[],"_cs_cves":[],"_cs_exploited":false,"_cs_has_poc":false,"_cs_poc_references":[],"_cs_products":["Firefox","Thunderbird"],"_cs_severities":["critical"],"_cs_tags":["use-after-free","firefox","thunderbird","CVE-2026-4711"],"_cs_type":"advisory","_cs_vendors":["Mozilla"],"content_html":"\u003cp\u003eCVE-2026-4711 describes a use-after-free vulnerability affecting the Widget: Cocoa component in Mozilla products. Specifically, Firefox versions prior to 149, Firefox ESR versions prior to 140.9, Thunderbird versions prior to 149, and Thunderbird versions prior to 140.9 are vulnerable. A use-after-free vulnerability occurs when an application attempts to use memory that has already been freed, which can lead to crashes, arbitrary code execution, or other unexpected behavior. While the specific exploitation details are not provided in the source material, the high CVSS score (9.8) indicates a critical vulnerability with a high potential impact. Exploitation would likely involve crafting a malicious web page or email that triggers the vulnerability when processed by the vulnerable application. This vulnerability was reported and patched by Mozilla.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eAn attacker crafts a malicious web page or email.\u003c/li\u003e\n\u003cli\u003eThe victim opens the malicious web page in a vulnerable version of Firefox or views the malicious email in a vulnerable version of Thunderbird.\u003c/li\u003e\n\u003cli\u003eThe malicious content triggers the use-after-free vulnerability in the Widget: Cocoa component.\u003c/li\u003e\n\u003cli\u003eThe vulnerable component attempts to access the freed memory.\u003c/li\u003e\n\u003cli\u003eThe attacker gains control of the freed memory by allocating new memory in its place.\u003c/li\u003e\n\u003cli\u003eThe attacker overwrites the memory with malicious code.\u003c/li\u003e\n\u003cli\u003eWhen the application attempts to use the original memory, it executes the attacker's code.\u003c/li\u003e\n\u003cli\u003eThe attacker achieves arbitrary code execution on the victim's machine.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of this use-after-free vulnerability could allow a remote attacker to execute arbitrary code on the victim's system. Given the wide use of Firefox and Thunderbird, a successful exploit could impact a large number of users. The vulnerability allows for complete compromise of the confidentiality, integrity, and availability of the affected system.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eUpgrade Firefox to version 149 or later to patch CVE-2026-4711.\u003c/li\u003e\n\u003cli\u003eUpgrade Firefox ESR to version 140.9 or later to patch CVE-2026-4711.\u003c/li\u003e\n\u003cli\u003eUpgrade Thunderbird to version 149 or later to patch CVE-2026-4711.\u003c/li\u003e\n\u003cli\u003eUpgrade Thunderbird ESR to version 140.9 or later to patch CVE-2026-4711.\u003c/li\u003e\n\u003cli\u003eMonitor web server logs for unusual activity related to Firefox user agents, and deploy the Sigma rule \u003ccode\u003etitle: \u0026quot;Detect Exploitation Attempt of CVE-2026-4711\u0026quot;\u003c/code\u003e to detect potential exploitation attempts in web traffic.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2024-01-03T14:30:00Z","date_published":"2024-01-03T14:30:00Z","id":"https://feed.craftedsignal.io/briefs/2024-01-firefox-use-after-free/","summary":"A use-after-free vulnerability in the Widget: Cocoa component of Mozilla Firefox (versions less than 149), Firefox ESR (less than 140.9), Thunderbird (less than 149), and Thunderbird (less than 140.9) could lead to arbitrary code execution.","title":"Mozilla Firefox Use-After-Free Vulnerability in Widget: Cocoa Component (CVE-2026-4711)","url":"https://feed.craftedsignal.io/briefs/2024-01-firefox-use-after-free/"}],"language":"en","title":"CraftedSignal Threat Feed - CVE-2026-4711","version":"https://jsonfeed.org/version/1.1"}