CVE-2026-2762 is an integer overflow vulnerability located within the JavaScript Standard Library component of Mozilla Firefox. Integer overflows occur when an arithmetic operation attempts to create a numeric value that exceeds the maximum size the data type can hold, causing wraparound and potentially leading to memory corruption. In this case, the vulnerability affects Firefox versions earlier than 148 and Firefox ESR versions earlier than 140.8. The flaw could be triggered by maliciously crafted JavaScript code executed in the browser, which may lead to memory corruption, enabling attackers to execute arbitrary code, crash the browser, or bypass security mechanisms. The vulnerability does not require user authentication and may not require user interaction beyond visiting a malicious or compromised website. No public exploits have been reported yet, but the nature of the vulnerability and the widespread use of Firefox make it a significant risk. The absence of a CVSS score suggests the vulnerability was recently disclosed and is pending detailed scoring. Mozilla is expected to release patches addressing this issue, and users are advised to update promptly. The vulnerability highlights the importance of secure coding practices in browser JavaScript engines and the risks posed by integer overflow bugs in complex software components.

The potential impact of CVE-2026-2762 is substantial for organizations and individual users worldwide. Successful exploitation could allow attackers to execute arbitrary code within the context of the browser, potentially leading to full system compromise if combined with other vulnerabilities or privilege escalation techniques. Confidentiality could be breached by stealing sensitive information accessible through the browser, including session tokens, passwords, and personal data. Integrity could be compromised by injecting malicious scripts or altering web content. Availability may be affected if exploitation causes browser crashes or denial of service. Organizations relying on Firefox for secure web access, including government agencies, financial institutions, and enterprises, face increased risk of targeted attacks. The lack of known exploits currently provides a window for proactive patching and mitigation. However, once exploit code becomes available, the threat level will escalate rapidly due to the widespread deployment of vulnerable Firefox versions.

1. Immediately monitor Mozilla’s official channels for the release of security patches addressing CVE-2026-2762 and apply updates to Firefox (version 148 or later) and Firefox ESR (version 140.8 or later) as soon as they become available. 2. Employ enterprise patch management solutions to ensure timely deployment of updates across all organizational endpoints. 3. Use browser security features such as sandboxing, strict content security policies (CSP), and disabling unnecessary JavaScript execution where feasible to reduce attack surface. 4. Educate users to avoid visiting untrusted or suspicious websites that could host malicious JavaScript payloads. 5. Implement network-level protections such as web filtering and intrusion detection systems to detect and block exploit attempts targeting this vulnerability. 6. Conduct regular security assessments and penetration testing to identify potential exploitation vectors related to browser vulnerabilities. 7. Maintain up-to-date backups and incident response plans to mitigate impact in case of successful exploitation. 8. Consider deploying endpoint detection and response (EDR) tools capable of identifying anomalous browser behavior indicative of exploitation attempts.