CVE-2026-6753 is a vulnerability in the WebRTC component of Mozilla Firefox caused by incorrect boundary conditions, classified under CWE-119 and CWE-787. This issue was addressed and fixed in Firefox 150 and Firefox ESR 140.10. The vulnerability has a CVSS v3.1 base score of 7.3 (high severity) with network attack vector, low attack complexity, no privileges required, no user interaction, and impacts confidentiality, integrity, and availability. The Mozilla security advisories MFSA2026-30 and MFSA2026-32 confirm the fix and provide additional context on related memory safety bugs fixed in these releases.

The vulnerability could allow an attacker to exploit incorrect boundary conditions in the WebRTC component, potentially leading to memory corruption that affects confidentiality, integrity, and availability of the affected system. Although no known exploits in the wild have been reported, the high CVSS score indicates a significant risk if exploited.

This vulnerability is fixed in Firefox 150 and Firefox ESR 140.10. Users and administrators should update affected Firefox and Thunderbird versions to these or later releases to remediate the issue. Mozilla manages the patching for these products, and no additional mitigation steps are required beyond applying the official updates.