CVE-2026-4714 describes a vulnerability caused by incorrect boundary conditions in the Audio/Video component of Mozilla Firefox. This vulnerability was fixed in Firefox 149 and Firefox ESR 140.9. It is one of multiple high-impact memory safety and boundary condition issues addressed in these releases. The CVSS 3.1 score is 7.5 (high), indicating network attack vector, low attack complexity, no privileges required, no user interaction, and impact limited to availability (denial of service). The vendor advisory confirms the fix availability and references the specific bug report (Bug 2018126).

The vulnerability can cause denial of service due to incorrect boundary conditions in the Audio/Video component, potentially leading to application crashes or instability. There is no evidence of confidentiality or integrity impact. No known exploits in the wild have been reported. The overall impact is rated high due to the potential for disruption of service.

Mozilla has released official fixes for this vulnerability in Firefox 149 and Firefox ESR 140.9. Users and administrators should update to these versions or later to remediate the issue. Since this is a client-side application vulnerability, updating the browser is the primary and effective mitigation. No additional vendor-recommended mitigations or workarounds are indicated.