CVE-2026-21004: DoS in Samsung Smart Switch

The primary impact of CVE-2026-21004 is a denial of service. An attacker, positioned physically near a device running a vulnerable version of Smart Switch, can exploit this flaw to render the application unresponsive. This could interrupt ongoing data transfers, prevent users from backing up their devices, or hinder other critical functions managed through Smart Switch. The attack requires physical proximity, limiting the immediate blast radius, but could be disruptive in environments where Smart Switch is frequently used, such as shared workspaces or public charging stations. While the vulnerability doesn't directly lead to data exfiltration, the disruption caused by the DoS could be leveraged as a distraction for other malicious activities.

1. Reserved2025-12-11
2. Published2026-03-16
3. EPSS updated2026-03-23

The primary mitigation for CVE-2026-21004 is to upgrade Samsung Smart Switch to version 3.7.69.15 or later. If an immediate upgrade is not feasible due to compatibility issues or system downtime requirements, consider temporarily disabling Smart Switch when not in use to reduce the attack surface. While a direct WAF rule is not applicable, restricting physical access to devices running vulnerable versions of Smart Switch can significantly reduce the risk. There are no specific Sigma or YARA rules available for this vulnerability at this time.