CVE-2026-16379 in Firefox
Summary
by MITRE • 07/21/2026
Privilege escalation in the DOM: Content Processes component. This vulnerability was fixed in Firefox 153 and Firefox ESR 140.13.
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Analysis
by VulDB Data Team • 07/21/2026
This privilege escalation vulnerability exists within the Document Object Model content processes component of Mozilla Firefox, representing a critical security flaw that allows attackers to elevate their privileges beyond normal user boundaries. The vulnerability specifically affects how Firefox handles certain DOM operations within its content process architecture, creating an opportunity for malicious actors to execute code with elevated permissions. This issue was addressed in Firefox version 153 and Firefox ESR version 140.13, which included patches to strengthen the security boundaries between different process components.
The technical nature of this flaw stems from insufficient validation mechanisms within the DOM content processing subsystem, where malicious web content could potentially exploit improper access controls or memory handling behaviors to gain unauthorized system privileges. The vulnerability operates at the intersection of browser security models and web content execution environments, specifically targeting the isolation mechanisms that separate user-generated content from privileged browser operations. This type of vulnerability typically falls under CWE-284 which describes improper access control scenarios, and may also relate to CWE-122 which deals with buffer overflow conditions that can lead to privilege escalation.
The operational impact of this vulnerability extends beyond simple browser exploitation as it provides attackers with a pathway to potentially compromise entire user systems. When successfully exploited, the privilege escalation could allow threat actors to execute arbitrary code with system-level privileges, access sensitive files, modify browser configurations, or even establish persistent backdoors. The affected content processes component represents a critical attack surface since it handles the rendering and execution of web content, making this vulnerability particularly dangerous in environments where users regularly interact with untrusted web materials.
Security mitigations for this vulnerability involve immediate deployment of the patched Firefox versions mentioned in the advisory, along with comprehensive browser hardening measures that include sandboxing enhancements and strict content security policy enforcement. Organizations should implement regular update management procedures to ensure timely patch deployment across all affected systems. The fix likely includes enhanced process isolation controls, stricter DOM access validation, and improved memory management practices within the content processes. Additionally, security teams should monitor for any related exploitation attempts through network traffic analysis and browser telemetry data, as this type of vulnerability often manifests through sophisticated attack vectors that may leverage multiple techniques to achieve privilege escalation.