CVE-2026-4690: Mozilla Firefox, Firefox ESR, and Thunderbird XPCOM Sandbox Escape
A sandbox escape vulnerability, identified as CVE-2026-4690, exists in the XPCOM component of Mozilla Firefox, Firefox ESR, and Thunderbird due to incorrect boundary conditions and an integer overflow, potentially allowing an attacker to execute arbitrary code outside the sandbox.
CVE-2026-4690 is a critical vulnerability affecting Mozilla Firefox, Firefox ESR, and Thunderbird. The root cause lies in incorrect boundary conditions coupled with an integer overflow within the XPCOM component. Successful exploitation allows an attacker to bypass the sandbox protections, potentially leading to arbitrary code execution outside the confines of the browser’s security measures. The vulnerability impacts Firefox versions earlier than 149, Firefox ESR versions prior to 115.34 and…
Detection coverage 2
Detect Firefox XPCOM Integer Overflow Attempt
highDetects potential exploitation attempts targeting the XPCOM integer overflow vulnerability in Firefox by monitoring for abnormal process creation events originating from the Firefox process with suspicious command-line arguments.
Detect Thunderbird XPCOM Integer Overflow Attempt
highDetects potential exploitation attempts targeting the XPCOM integer overflow vulnerability in Thunderbird by monitoring for abnormal process creation events originating from the Thunderbird process with suspicious command-line arguments.
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Indicators of compromise
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