The vulnerability identified as CVE-2026-2762 involves an integer overflow in the JavaScript: Standard Library component of Mozilla Firefox. Integer overflow vulnerabilities can lead to memory corruption and potentially allow attackers to execute arbitrary code or cause denial of service. Mozilla fixed this issue in Firefox 148 and Firefox ESR 140.8 as part of a security update addressing multiple high-impact bugs. The CVSS v3.1 base score of 9.8 reflects network attack vector, low attack complexity, no privileges or user interaction required, and high impact on confidentiality, integrity, and availability.

Successful exploitation of this integer overflow could allow an attacker to execute arbitrary code, compromise user confidentiality, integrity, and availability of the affected system. Given the high CVSS score and the nature of the vulnerability, it poses a critical risk to users running affected versions of Firefox prior to 148 and Firefox ESR prior to 140.8. No known exploits in the wild have been reported at the time of disclosure.

Mozilla has released official fixes for this vulnerability in Firefox 148 and Firefox ESR 140.8. Users and administrators should update affected Firefox installations to version 148 or later, or Firefox ESR 140.8 or later, to mitigate this vulnerability. No additional mitigation steps are required beyond applying the official update.