CVE-2026-113400 in Firefox
Summary
by MITRE • 10/20/2026
Uninitialized memory in the Audio/Video: cubeb component. This vulnerability was fixed in Firefox 158.0.1.
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Analysis
by VulDB Data Team • 10/20/2026
The identified vulnerability resides within the cubeb audio processing subsystem of Mozilla Firefox, specifically involving uninitialized memory access. The cubeb library serves as a critical abstraction layer that facilitates cross-platform audio and video handling, managing interactions between the browser engine and underlying operating system sound APIs. When this component processes specific media streams or handles complex audio routing scenarios, it may allocate memory buffers without properly initializing all allocated bytes to zero or defined default values. This oversight creates a state where portions of the buffer contain residual data from previous allocations or stack contents that were not cleared before being used in subsequent operations.
From a technical perspective, this flaw constitutes an uninitialized variable vulnerability, which aligns with Common Weakness Enumeration identifier CWE-457. The core issue arises when the application reads from these memory locations expecting valid, sanitized input but instead retrieves unpredictable data. In the context of multimedia processing, such as decoding audio tracks or managing real-time communication streams, this can lead to erratic behavior in signal processing algorithms. If an attacker can influence the allocation patterns or trigger specific code paths that expose these uninitialized regions, they may be able to read sensitive information stored elsewhere in memory, leading to a potential Information Disclosure vulnerability classified under CWE-200.
The operational impact of this flaw is primarily tied to confidentiality and stability rather than direct remote code execution. While modern browser sandboxing mitigates the risk of arbitrary code execution through uninitialized data alone, the leakage of internal state or cryptographic keys stored in adjacent memory regions remains a significant concern. Furthermore, depending on how the uninitialized values are interpreted by subsequent logic, there is a possibility of causing crashes or denial-of-service conditions if invalid pointers or malformed parameters derived from garbage data are passed to system calls or lower-level libraries. This aligns with ATT&CK technique T1005, which describes Data from Local System Retrieval, as the vulnerability allows for potential exfiltration of memory contents that should remain isolated within the browser process.
Mitigation strategies focus on both immediate patching and long-term defensive coding practices. The primary remediation is to upgrade Mozilla Firefox to version 158.0.1 or later, where developers have implemented proper initialization routines for all buffers allocated by the cubeb component. For organizations managing large fleets of browsers, automated deployment tools should be utilized to ensure rapid distribution of this update. Additionally, security engineering teams should enforce static analysis rules that detect uninitialized variable usage and mandate memory sanitization during allocation phases in multimedia processing modules. Regular auditing of third-party libraries like cubeb is also recommended to identify similar patterns before they are integrated into the main browser codebase, ensuring robustness against future instances of CWE-457.