CVE-2026-92057 in Firefox
Summary
by MITRE • 09/15/2026
Mitigation bypass in the Enterprise Policies component. This vulnerability was fixed in Firefox 156 and Firefox ESR 153.3.
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Analysis
by VulDB Data Team • 09/15/2026
The identified security issue represents a critical failure within the enterprise policy management subsystem of Mozilla Firefox, specifically affecting versions prior to 156 for standard releases and before 153.3 for Extended Support Release channels. This vulnerability is classified as a mitigation bypass, indicating that established security controls designed to enforce organizational or administrative restrictions were successfully circumvented by an attacker or malicious script. In enterprise environments, policies are typically deployed via configuration files such as autoconfig.js or through centralized management tools like Microsoft Endpoint Manager to restrict browser capabilities, including disabling add-ons, enforcing proxy settings, and preventing users from modifying privacy or security preferences. The flaw in the Enterprise Policies component suggests that these enforced restrictions were not properly validated or applied during specific operational states, allowing unauthorized modifications to the browser's configuration state despite administrative prohibitions.
From a technical perspective, this vulnerability likely stems from an insufficient check on policy enforcement logic within the JavaScript engine or the preference system of Firefox. When policies are loaded, they should override user preferences and prevent subsequent changes through the graphical interface or programmatic API calls. The bypass indicates that under certain conditions, such as during specific initialization sequences or when interacting with particular web content, the browser failed to maintain the integrity of these locked settings. This could allow a malicious website or a compromised extension to alter critical security configurations, effectively neutralizing defenses like clickjacking protection, cross-site scripting filters, or strict origin policies that were intended to be immutable by end users. The existence of such a bypass undermines the trust model required for managed devices, where administrators rely on consistent enforcement of baseline security standards across all endpoints in their network.
The operational impact of this vulnerability is significant for organizations relying on Firefox as their primary web browser. By circumventing enterprise policies, an attacker could potentially disable content blockers, enable unsafe add-ons, or modify proxy settings to facilitate man-in-the-middle attacks. This capability effectively turns a managed device into an unmanaged one from the perspective of security policy enforcement. For example, if a policy is set to block all non-HTTPS traffic or restrict access to specific domains, this vulnerability could allow such restrictions to be lifted dynamically during a browsing session. Consequently, sensitive corporate data becomes more susceptible to exfiltration through unauthorized channels, and the overall attack surface of the endpoint increases substantially as multiple layers of defense are removed simultaneously without user consent or administrative approval.
To address this risk, immediate action is required to update all affected Firefox installations to version 156 for standard users and version 153.3 for ESR users. These releases contain patches that correct the logic errors within the Enterprise Policies component, ensuring that policy enforcement remains robust against bypass attempts. In addition to updating software, organizations should verify their current configuration files to ensure no legacy settings are inadvertently overriding newer security controls. It is also advisable to monitor browser logs and network traffic for anomalies indicative of policy manipulation, such as unexpected changes in proxy configurations or the loading of unsigned add-ons. Regular audits of enterprise policy deployment mechanisms can help identify any residual weaknesses before they are exploited by threat actors seeking to compromise managed endpoints.
This vulnerability aligns with CWE-250, which describes execution with unnecessary privileges, and more specifically relates to CWE-693, Protection Mechanism Failure, where the system fails to protect resources from unauthorized access or modification. In terms of offensive security frameworks, this flaw facilitates techniques associated with MITRE ATT&CK T1087, Account Discovery, by potentially allowing attackers to gather information about user privileges and configurations that should be hidden. It also relates to T1562, Impair Defenses, as the attacker actively disables or modifies security software settings to reduce detection capabilities. Understanding these classifications helps in mapping the vulnerability to broader threat intelligence models and prioritizing remediation efforts based on the potential for exploitation within specific enterprise contexts.