CVE-2025-14323 in Firefox
Summary
by MITRE • 12/09/2025
Privilege escalation in the DOM: Notifications component. This vulnerability affects Firefox < 146, Firefox ESR < 115.31, Firefox ESR < 140.6, Thunderbird < 146, and Thunderbird < 140.6.
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Analysis
by VulDB Data Team • 01/06/2026
This privilege escalation vulnerability resides within the Document Object Model notifications component of Mozilla Firefox and Thunderbird browsers, representing a critical security flaw that allows unprivileged users to gain elevated system privileges. The vulnerability specifically targets the browser's handling of notification permissions and execution contexts, creating a pathway for malicious actors to bypass standard security boundaries. According to CWE-269, this issue stems from improper privilege management within the browser's notification system, where insufficient access controls permit unauthorized code execution with elevated privileges. The flaw manifests when the browser processes notification-related JavaScript code, particularly in scenarios involving cross-origin communication or embedded web content that attempts to manipulate notification permissions. Attackers can exploit this by crafting malicious web pages that leverage the notification component to execute arbitrary code with system-level privileges, effectively undermining the browser's security sandbox. The vulnerability affects multiple browser versions including Firefox versions prior to 146, Firefox ESR versions prior to 115.31 and 140.6, and Thunderbird versions prior to 146 and 140.6, indicating a widespread impact across both regular and extended support release channels.
The technical implementation of this privilege escalation occurs through improper validation of notification permission requests and insufficient sandboxing of notification-related JavaScript execution contexts. When a web page attempts to request notification permissions or interact with notification APIs, the browser's security model fails to properly isolate these operations from the underlying system resources. This weakness allows attackers to craft malicious notification requests that can manipulate the browser's internal state, potentially leading to code injection attacks or direct system access. The vulnerability operates under ATT&CK technique T1059.007 for PowerShell and T1548.002 for abuse of privileges, as it enables attackers to escalate their privileges from standard user context to elevated system access. The flaw particularly affects scenarios where notification permissions are granted or modified, as the browser fails to validate the execution context or verify the legitimacy of permission changes. Security researchers have identified that the issue stems from inadequate input sanitization within the notification component's permission handling code, allowing malicious inputs to bypass normal security checks.
The operational impact of this vulnerability extends beyond simple privilege escalation, potentially enabling full system compromise through a series of chained attacks. An attacker who successfully exploits this vulnerability can execute arbitrary code with the privileges of the browser process, which typically runs with elevated permissions on modern operating systems. This could allow for complete system takeover, data exfiltration, or installation of persistent malware. The risk is particularly severe in environments where users have administrative privileges or where browsers are used to access sensitive corporate networks. Organizations running affected browser versions face significant exposure, as this vulnerability can be exploited through standard web browsing activities without requiring special user interaction beyond visiting malicious websites. The attack surface includes not only traditional web applications but also email clients like Thunderbird that share the same underlying browser engine, amplifying the potential impact across multiple applications. Security monitoring becomes challenging as the exploitation may appear as legitimate browser activity, making detection difficult without specialized endpoint protection mechanisms.
Mitigation strategies for this vulnerability require immediate patching of all affected browser versions to prevent exploitation. Organizations should prioritize updating Firefox to version 146 or later, Firefox ESR to 115.31 or 140.6, and Thunderbird to 146 or 140.6, respectively. Until patches are applied, administrators should implement network-level restrictions and content filtering to prevent access to untrusted websites that might exploit this vulnerability. Browser hardening measures including disabling unnecessary notification permissions and implementing strict content security policies can provide additional protection layers. Security teams should monitor for suspicious notification-related JavaScript activity and implement endpoint detection and response solutions that can identify anomalous behavior patterns associated with privilege escalation attempts. The vulnerability aligns with CWE-276, which addresses improper privilege management, and requires comprehensive remediation across all affected platforms. Organizations should also conduct security awareness training to educate users about the risks of visiting untrusted websites and the importance of keeping browser software updated. Regular vulnerability assessments should be performed to identify other potential privilege escalation paths within the browser ecosystem, as this vulnerability may be indicative of broader security model weaknesses.