CVE-2026-2762 describes an integer overflow vulnerability within the JavaScript: Standard Library component of Mozilla Firefox. Integer overflow can lead to memory corruption or unexpected behavior, potentially allowing an attacker to execute arbitrary code or cause a denial of service. Mozilla fixed this vulnerability in Firefox 148 and Firefox ESR 140.8 as part of a broader security update addressing multiple high-impact issues. The vulnerability has a CVSS v3.1 base score of 9.8, reflecting its critical nature and ease of exploitation without privileges or user interaction.

The vulnerability could allow an attacker to cause memory corruption leading to arbitrary code execution or denial of service in affected Firefox versions prior to 148 and Firefox ESR prior to 140.8. The CVSS vector indicates network attack vector, low attack complexity, no privileges required, no user interaction, and high impact on confidentiality, integrity, and availability. No known exploits have been reported in the wild 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 these versions or later to remediate the issue. Since this is a client software vulnerability, patching is the primary and recommended mitigation. No additional vendor-recommended mitigations or workarounds are indicated.