Mozilla CVE-2026-16401

Mozilla Firefox's Data Loss Prevention component contains a critical privilege escalation vulnerability enabling attackers to bypass security controls and access sensitive company data. Organizations relying on Firefox with DLP policies face direct data breach risk. While technical severity is critical, near-term exploitation probability remains minimal (0.1%), providing time to respond before active threats emerge.

Within 24 hours, identify and catalog all Firefox instances with active DLP components across your infrastructure, focusing on high-sensitivity departments such as finance, legal, and engineering; tighten privilege restrictions on Firefox processes to prevent low-privilege execution of untrusted content. Within 7 days, implement enhanced process monitoring and alerting for anomalous Firefox behavior; consider restricting DLP-enabled Firefox to higher-security workstations if operationally feasible and maintain detailed audit logs. Within 30 days, monitor Mozilla security advisories regularly for patch availability and develop a deployment procedure; if patch delivery extends beyond 60 days, evaluate alternative DLP solutions for the most sensitive workflows.

No vendor-released patch identified at time of analysis. Interim mitigations include disabling the DLP component where operationally feasible, restricting Firefox to low-privilege execution contexts, implementing network-based DLP solutions on critical data pathways, and hardening browser security policies to minimize likelihood of successful exploitation.