CVE-2026-2801 is a security vulnerability identified in Mozilla Firefox versions earlier than 148, specifically within the JavaScript WebAssembly component. The issue stems from incorrect boundary condition checks during WebAssembly code execution, which can lead to memory corruption. WebAssembly is a low-level bytecode format designed to run high-performance applications in browsers, and improper boundary validation can allow attackers to read or write outside intended memory areas. This vulnerability could be exploited by an attacker who crafts malicious WebAssembly modules embedded in web pages, potentially leading to arbitrary code execution, privilege escalation, or denial of service. The flaw does not require prior authentication but does require the victim to load malicious content, which is a common attack vector in browser vulnerabilities. Currently, no exploits have been reported in the wild, and no official patches or CVSS scores have been released. However, the vulnerability's nature suggests a significant risk due to the critical role of WebAssembly in modern web applications and the widespread deployment of Firefox. The lack of detailed CWE classification and patch information indicates that this is an early disclosure, and users should anticipate updates from Mozilla. The vulnerability highlights the importance of secure boundary checks in memory management within browser engines to prevent exploitation.

The potential impact of CVE-2026-2801 is substantial for organizations and users worldwide relying on Mozilla Firefox for web browsing. Successful exploitation could lead to arbitrary code execution within the browser context, enabling attackers to compromise user data, install malware, or pivot into internal networks. Memory corruption vulnerabilities in WebAssembly can also cause browser crashes, resulting in denial of service and reduced availability. Given Firefox's significant market share, especially in privacy-conscious and open-source communities, a large number of endpoints are exposed. Enterprises using Firefox in their environments may face increased risk of targeted attacks leveraging this vulnerability. Additionally, web applications that rely heavily on WebAssembly for performance could be indirectly affected if users disable or restrict WebAssembly as a mitigation. The absence of known exploits currently reduces immediate risk, but the vulnerability's characteristics make it a likely target for future exploitation once details become widely known. Overall, the threat could compromise confidentiality, integrity, and availability of affected systems if exploited.

To mitigate CVE-2026-2801, organizations and users should prioritize upgrading Mozilla Firefox to version 148 or later once the patch is released. Until an official patch is available, consider the following specific measures: 1) Disable or restrict WebAssembly execution in Firefox via browser configuration settings or enterprise policies to reduce the attack surface, especially in high-risk environments. 2) Employ network-level protections such as web filtering and intrusion prevention systems to block access to known malicious sites or suspicious WebAssembly content. 3) Monitor browser crash reports and unusual behavior indicative of exploitation attempts. 4) Educate users about the risks of visiting untrusted websites and encourage cautious browsing habits. 5) Use endpoint detection and response (EDR) tools to detect anomalous process behavior related to browser exploitation. 6) Stay informed through Mozilla security advisories and apply patches promptly upon release. These targeted actions go beyond generic advice by focusing on WebAssembly-specific controls and proactive monitoring tailored to this vulnerability.