CVE-2026-4724 in Firefox
Summary
by MITRE • 03/24/2026
Undefined behavior in the Audio/Video component. This vulnerability affects Firefox < 149 and Thunderbird < 149.
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Analysis
by VulDB Data Team • 03/28/2026
This vulnerability represents a critical undefined behavior flaw within the audio/video component of Mozilla Firefox and Thunderbird applications. The issue stems from improper handling of multimedia data structures during processing, creating opportunities for memory corruption and potential code execution. When these applications process malformed or malicious audio/video content, the undefined behavior can lead to unpredictable program states that adversaries may exploit to gain control over affected systems. The vulnerability specifically impacts versions prior to 149, indicating it has been present for multiple release cycles and likely represents a long-standing issue in the multimedia processing pipeline.
The technical nature of this vulnerability aligns with CWE-755 weakness category, which encompasses improper handling of exceptional conditions and undefined behaviors in software components. This classification suggests the flaw occurs during normal operation when the application encounters unexpected data patterns or processing scenarios that were not adequately anticipated during development. The audio/video component in question likely handles complex multimedia decoding and rendering operations where buffer overflows, memory access violations, or state corruption can occur when processing malformed input streams. Attackers can leverage this undefined behavior through crafted media content that triggers specific processing paths within the multimedia engine, potentially leading to arbitrary code execution with the privileges of the affected application.
The operational impact of this vulnerability extends beyond simple application instability, as it creates a significant attack surface for remote code execution exploits. When users encounter maliciously crafted audio or video files, the undefined behavior can result in crashes, memory corruption, or complete system compromise depending on the execution context. This vulnerability is particularly concerning in the context of the ATT&CK framework's execution tactics, as it provides adversaries with a method to execute arbitrary code on target systems. The affected applications represent common attack vectors since they frequently process multimedia content from untrusted sources, making this vulnerability highly exploitable in real-world scenarios. Organizations using affected versions face substantial risk as the vulnerability can be triggered through various means including web browsing, email attachments, or multimedia file processing.
Mitigation strategies should focus on immediate version upgrades to Firefox 149 and Thunderbird 149, which contain the necessary patches to address the undefined behavior. System administrators should prioritize deployment of these updates across all affected endpoints while monitoring for any signs of exploitation attempts. Additional protective measures include implementing content filtering solutions that can identify and block malicious multimedia content, enabling sandboxing features within the applications, and maintaining comprehensive network monitoring to detect potential exploitation attempts. Security teams should also consider deploying web application firewalls and implementing strict access controls to limit exposure to untrusted multimedia content sources. The vulnerability demonstrates the importance of robust input validation and proper error handling in multimedia processing components, as undefined behaviors in such critical system areas can lead to severe security consequences. Organizations should conduct thorough vulnerability assessments to identify any other potentially affected components and ensure that all multimedia processing functionality adheres to secure coding practices and industry standards.