CVE-2026-2773 in Firefox
Summary
by MITRE • 02/24/2026
Incorrect boundary conditions in the Web Audio component. This vulnerability was fixed in Firefox 148, Firefox ESR 115.33, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.
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Analysis
by VulDB Data Team • 07/01/2026
The vulnerability identified as CVE-2026-2773 represents a critical boundary condition flaw within the Web Audio component of Mozilla Firefox and Thunderbird applications. This issue stems from inadequate input validation and memory management practices that occur when processing audio data streams through the browser's web audio API implementation. The flaw manifests when the application fails to properly validate array bounds or buffer sizes during audio processing operations, creating potential pathways for memory corruption and arbitrary code execution.
The technical nature of this vulnerability places it within the realm of software security weaknesses categorized under CWE-129, which specifically addresses insufficient boundary checking in programming implementations. This weakness allows attackers to manipulate audio data structures in ways that bypass normal safety mechanisms designed to prevent buffer overflows or underflows. The vulnerability affects multiple versions of Firefox and Thunderbird across different release channels, indicating a widespread impact that extends beyond standard browser updates to include extended support releases and email clients that utilize the same underlying web audio infrastructure.
Operational impact assessment reveals that successful exploitation of this vulnerability could enable remote attackers to execute arbitrary code on affected systems with the privileges of the user running the browser or email client. The attack surface is particularly concerning given that web audio APIs are commonly used in modern web applications, making this vulnerability potentially exploitable through standard web browsing activities. Attackers could leverage this flaw to deliver malicious audio content that triggers the boundary condition error, potentially leading to complete system compromise or data exfiltration. The vulnerability's presence in both Firefox and Thunderbird applications expands the potential attack vectors significantly, as users may be exposed through email attachments or web-based audio applications.
Mitigation strategies should prioritize immediate application of vendor-provided security patches and updates to the affected versions. Organizations should implement network-level protections including web application firewalls and content filtering systems that can detect and block suspicious audio content patterns. Security teams should also consider implementing browser hardening measures such as disabling unnecessary web audio APIs for non-essential applications and monitoring for anomalous audio processing behaviors. Additionally, regular security assessments should be conducted to identify and remediate similar boundary condition vulnerabilities in other browser components and third-party libraries that may be susceptible to similar flaws. The ATT&CK framework categorizes this vulnerability under techniques related to code injection and privilege escalation, emphasizing the need for layered defense strategies that address both the immediate vulnerability and broader exploitation patterns.