CVE-2026-6753 is a vulnerability involving incorrect boundary conditions in the WebRTC component of Mozilla Firefox. It is classified under CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer). The CVSS v3.1 base score is 7.3 (high), reflecting network attack vector, low attack complexity, no privileges required, no user interaction, and impacts to confidentiality, integrity, and availability. Mozilla fixed this vulnerability in Firefox 150 and Firefox ESR 140.10, as documented in their security advisories MFSA 2026-30 and MFSA 2026-32. The advisories confirm that the issue is resolved in these versions and related Thunderbird releases. No active exploitation has been reported.

The vulnerability could allow an attacker to exploit improper boundary checks in the WebRTC component, potentially leading to memory corruption affecting confidentiality, integrity, and availability of the affected system. However, there are no known exploits in the wild. The impact is rated high by Mozilla and the CVSS score supports this severity level.

This vulnerability has been fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird ESR 140.10. Users and administrators should update to these versions or later to remediate the issue. No additional mitigation steps are required beyond applying the official updates as per Mozilla's advisories.