CVE-2026-21051: WLAN Security Privilege Escalation Flaw

CVE-2026-21051 Overview

CVE-2026-21051 is an incorrect default permissions vulnerability in the WLAN security component of Samsung Mobile devices prior to the Security Maintenance Release (SMR) for July 2026 Release 1. The flaw allows local attackers to configure TencentWifiSecurity settings without proper authorization checks. The issue affects the permission model enforced on WLAN security configuration interfaces exposed to local applications on the device.

Samsung addressed the vulnerability in the Samsung Security Update July 2026.

Critical Impact
A local attacker with code execution on the device can modify Wi-Fi security settings tied to TencentWifiSecurity, potentially weakening network protection posture without user interaction.

Affected Products

Samsung Mobile devices running affected Android firmware prior to SMR Jul-2026 Release 1
Samsung firmware exposing the TencentWifiSecurity configuration interface
Samsung WLAN security subsystem with incorrect default permissions

Discovery Timeline

2026-07-10 - CVE-2026-21051 published to NVD
2026-07-10 - Samsung releases SMR Jul-2026 Release 1 addressing the vulnerability
2026-07-10 - Last updated in NVD database

Technical Details for CVE-2026-21051

Vulnerability Analysis

The vulnerability stems from incorrect default permissions applied to the WLAN security configuration surface on affected Samsung devices. The TencentWifiSecurity settings interface does not enforce sufficient access control on callers. As a result, an application running with local privileges can invoke configuration operations that should require elevated or system-level permissions.

This is a configuration and design flaw classified as Insecure Permissions. The confidentiality and integrity impact is limited to low, and there is no availability impact. Exploitation requires local access to the device but does not require user interaction or prior authentication with the affected component.

Root Cause

The root cause is a permission misconfiguration on an exported component or system service handling TencentWifiSecurity settings. The default permission scope allows callers below the intended privilege level to invoke configuration APIs. This bypasses the trust boundary that should separate privileged Wi-Fi security policy management from unprivileged application code.

Attack Vector

An attacker must first achieve local code execution on the device, typically through a malicious application installed by the user or through another vulnerability providing app-level access. Once resident, the attacker's code issues configuration calls against the TencentWifiSecurity interface. Because default permissions are incorrect, the calls succeed without a permission denial from the platform.

Samsung has not published exploitation details, and no public proof-of-concept is available. See the Samsung Security Update July 2026 advisory for vendor guidance.

Detection Methods for CVE-2026-21051

Indicators of Compromise

Unexpected changes to Wi-Fi security configuration state on Samsung devices running pre-SMR Jul-2026 Release 1 firmware
Installed applications requesting or invoking TencentWifiSecurity related interfaces without a legitimate business purpose
Devices operating on firmware build strings predating the July 2026 Samsung security patch level

Detection Strategies

Inventory Samsung mobile devices in the fleet and identify those reporting a security patch level earlier than 2026-07-01
Review installed application permissions and package manifests for calls into Samsung WLAN security or Tencent-related components
Correlate mobile device management (MDM) telemetry with firmware version data to flag non-compliant devices

Monitoring Recommendations

Enable MDM policies that report Android security patch level and flag devices below the July 2026 baseline
Monitor for installation of unvetted applications on managed Samsung devices
Alert on Wi-Fi profile or security setting changes that occur outside of managed configuration channels

How to Mitigate CVE-2026-21051

Immediate Actions Required

Apply Samsung SMR Jul-2026 Release 1 or later to all affected Samsung mobile devices
Restrict installation of untrusted applications through MDM policy enforcement on managed devices
Audit devices for the presence of applications that interact with TencentWifiSecurity components

Patch Information

Samsung addressed CVE-2026-21051 in the July 2026 Security Maintenance Release. Administrators should ensure managed devices report an Android security patch level of 2026-07-01 or later. Full details are available in the Samsung Security Update July 2026 bulletin.

Workarounds

Limit device access to trusted users only and enforce application allowlisting where supported
Use enterprise MDM to restrict installation sources to the managed Google Play or Galaxy Store catalog
Configure Wi-Fi profiles centrally through MDM so that any local configuration drift can be detected and reverted

bash

# Verify Android security patch level on a managed Samsung device via adb
adb shell getprop ro.build.version.security_patch
# Expected value for patched devices: 2026-07-01 or later