{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata. Fed continuously.","feed_url":"https://feed.craftedsignal.io/tags/cve-2026-4686/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":["high"],"_cs_tags":["cve-2026-4686","denial-of-service","firefox","thunderbird"],"_cs_type":"advisory","_cs_vendors":["Mozilla"],"content_html":"\u003cp\u003eCVE-2026-4686 describes a vulnerability affecting Mozilla Firefox and Thunderbird due to improper boundary conditions within the Graphics: Canvas2D component. This flaw can be triggered in Firefox versions prior to 149, Firefox ESR versions less than 115.34 and 140.9, and Thunderbird versions less than 149 and 140.9. An unauthenticated remote attacker could potentially exploit this vulnerability to cause a denial-of-service condition by crafting malicious web content that triggers the improper boundary conditions within the Canvas2D rendering engine. This could lead to resource exhaustion or application crashes, impacting availability for legitimate users. Defenders should prioritize patching affected versions of Firefox and Thunderbird.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eThe attacker crafts a malicious HTML page containing JavaScript that leverages the Canvas2D API.\u003c/li\u003e\n\u003cli\u003eThe malicious JavaScript generates specific Canvas2D drawing operations designed to trigger the incorrect boundary condition.\u003c/li\u003e\n\u003cli\u003eThe victim visits the malicious webpage using a vulnerable version of Firefox or Thunderbird.\u003c/li\u003e\n\u003cli\u003eThe browser's Canvas2D rendering engine attempts to process the malformed drawing operations.\u003c/li\u003e\n\u003cli\u003eThe improper boundary conditions lead to excessive resource consumption (e.g., memory allocation or CPU usage).\u003c/li\u003e\n\u003cli\u003eThe affected process becomes unresponsive or crashes due to resource exhaustion.\u003c/li\u003e\n\u003cli\u003eThe user experiences a denial-of-service condition, where the browser or email client becomes unusable.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of CVE-2026-4686 can lead to a denial-of-service condition in Firefox and Thunderbird. While the exact number of potential victims is unknown, any user running vulnerable versions of the software is at risk. This can disrupt productivity, especially for users who rely on these applications for web browsing or email communication. The vulnerability can be triggered remotely without requiring user interaction beyond visiting a malicious webpage.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eUpgrade Mozilla Firefox to version 149 or later to remediate CVE-2026-4686.\u003c/li\u003e\n\u003cli\u003eUpgrade Mozilla Firefox ESR to version 115.34 or 140.9 or later.\u003c/li\u003e\n\u003cli\u003eUpgrade Thunderbird to version 149 or later to remediate CVE-2026-4686.\u003c/li\u003e\n\u003cli\u003eDeploy the Sigma rule \u0026quot;Detect Canvas2D DoS Exploit Attempt\u0026quot; to identify potential exploitation attempts by monitoring JavaScript execution.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2024-01-25T12:00:00Z","date_published":"2024-01-25T12:00:00Z","id":"https://feed.craftedsignal.io/briefs/2024-01-25-firefox-canvas2d-dos/","summary":"CVE-2026-4686 is a high-severity vulnerability due to incorrect boundary conditions in the Canvas2D component of Mozilla Firefox and Thunderbird, potentially leading to a denial-of-service condition.","title":"Mozilla Firefox and Thunderbird Canvas2D Improper Boundary Conditions Vulnerability (CVE-2026-4686)","url":"https://feed.craftedsignal.io/briefs/2024-01-25-firefox-canvas2d-dos/"}],"language":"en","title":"CraftedSignal Threat Feed - Cve-2026-4686","version":"https://jsonfeed.org/version/1.1"}