Multiple vulnerabilities have been reported in Mozilla Firefox ESR. At the time of the advisory, their full details had not yet been published. An attacker can exploit them to cause currently unspecified effects. Further details are expected once analysis is complete.
Firefox ESR (Extended Support Release) is the version Mozilla provides for enterprise environments and other contexts where frequent updates are difficult to manage. It receives security patches but no feature updates between major versions.
Act Even Without Full Details
Incomplete technical details do not reduce the urgency: install the current Firefox update. In enterprise environments running Firefox ESR, push the update through your software distribution system. You can check your currently installed version via "Help" and "About Firefox".