Firefox Smart Window private browsing URL exfiltration (CVE-2026-20253)

Ibrahim Saud@tektrix

•updated Jun 30, 2026•2•0•4

Detects anomalous Firefox behavior consistent with CVE-2026-20253 exploitation, including unauthorized modification of Smart Window browser preferences (e.g., enabling the feature or redirecting the API endpoint) and suspicious child process creation following potential URL exfiltration events.