CVE-2026-6753

CVE-2026-6753 is a boundary condition vulnerability in the WebRTC component affecting Mozilla Firefox (version 150 and later), Firefox ESR (140.10 and later), Thunderbird (150 and later), and Thunderbird ESR (140.10 and later). This flaw allows incorrect handling of memory boundaries within the WebRTC implementation, potentially enabling unauthorized access or system compromise. The vulnerability carries a HIGH severity rating (CVSS 7.3) due to its network-based attack vector requiring no user interaction or special privileges. While the attack complexity is low, the impact is moderate across confidentiality, integrity, and availability, allowing attackers to potentially leak information, modify data, or degrade system functionality. There is currently no evidence of active exploitation in the wild, with no known public exploit code available and the vulnerability absent from the Known Exploited Vulnerabilities catalog. The relatively low EPSS score (0.00044) and inactive status on security hotlists suggest limited immediate threat, though organizations should still apply available patches as part of standard vulnerability management procedures.