{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata. Fed continuously.","feed_url":"https://feed.craftedsignal.io/tags/cve-2026-4699/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":["medium"],"_cs_tags":["cve-2026-4699","firefox","thunderbird","denial-of-service"],"_cs_type":"advisory","_cs_vendors":["Mozilla"],"content_html":"\u003cp\u003eCVE-2026-4699 describes a vulnerability in the Layout: Text and Fonts component of Mozilla Firefox and Thunderbird products. This vulnerability stems from incorrect boundary conditions, which can lead to unexpected behavior and potentially a denial-of-service. The vulnerability affects Firefox versions prior to 149, Firefox ESR versions prior to 115.34 and 140.9, and Thunderbird versions prior to 149 and 140.9. This was reported to Mozilla and assigned bug ID 2021863. Successful exploitation could result in instability or termination of the affected application. Defenders should prioritize patching affected Firefox and Thunderbird versions.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eAn attacker crafts a malicious HTML page or email containing specific text and font formatting.\u003c/li\u003e\n\u003cli\u003eThe user opens the crafted HTML page in Firefox or views the malicious email in Thunderbird.\u003c/li\u003e\n\u003cli\u003eThe Layout: Text and Fonts component attempts to render the text.\u003c/li\u003e\n\u003cli\u003eDue to the incorrect boundary conditions, the rendering process encounters an unexpected state.\u003c/li\u003e\n\u003cli\u003eThe application enters an infinite loop or attempts to access an invalid memory location.\u003c/li\u003e\n\u003cli\u003eThis causes the affected process to become unresponsive.\u003c/li\u003e\n\u003cli\u003eThe Firefox or Thunderbird application crashes, resulting in a denial-of-service.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of CVE-2026-4699 can lead to a denial-of-service condition on the affected system. An attacker could potentially disrupt the user's browsing or email activities. While the vulnerability has a CVSS v3.1 score of 7.5, the impact is limited to application instability. This vulnerability affects users of Firefox (versions \u0026lt; 149, ESR \u0026lt; 115.34, ESR \u0026lt; 140.9) and Thunderbird (versions \u0026lt; 149, \u0026lt; 140.9).\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 patch CVE-2026-4699.\u003c/li\u003e\n\u003cli\u003eUpgrade Mozilla Firefox ESR to version 115.3.4 or 140.9 or later to patch CVE-2026-4699.\u003c/li\u003e\n\u003cli\u003eUpgrade Mozilla Thunderbird to version 149 or 140.9 or later to patch CVE-2026-4699.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2024-01-03T12:00:00Z","date_published":"2024-01-03T12:00:00Z","id":"https://feed.craftedsignal.io/briefs/2024-01-firefox-thunderbird-cve-2026-4699/","summary":"CVE-2026-4699 describes an improper check for unusual or exceptional conditions in the Layout: Text and Fonts component of Mozilla Firefox and Thunderbird leading to a potential denial-of-service.","title":"Mozilla Firefox and Thunderbird Improper Boundary Condition Vulnerability (CVE-2026-4699)","url":"https://feed.craftedsignal.io/briefs/2024-01-firefox-thunderbird-cve-2026-4699/"}],"language":"en","title":"CraftedSignal Threat Feed - Cve-2026-4699","version":"https://jsonfeed.org/version/1.1"}