CVE-2026-20978: Samsung Android Auth Bypass Vulnerability

CVE-2026-20978 Overview

CVE-2026-20978 is an improper authorization vulnerability in Samsung's KnoxGuardManager component that affects Samsung Android devices. This security flaw allows local attackers to bypass the persistence configuration of the application, potentially undermining enterprise device management and security controls implemented through Samsung Knox.

Samsung Knox is a defense-grade mobile security platform built into Samsung devices, widely used by enterprises for secure device management. The KnoxGuardManager component is responsible for enforcing persistence configurations that prevent unauthorized modifications to managed device settings. This vulnerability compromises that protection mechanism.

Critical Impact

Local attackers can bypass KnoxGuardManager persistence configurations, potentially disabling enterprise security controls and device management policies on affected Samsung Android devices.

Affected Products

• Samsung Android 13.0 (all SMR releases prior to Feb-2026 Release 1)
• Samsung Android 14.0 (all SMR releases prior to Feb-2026 Release 1)
• Samsung Android 15.0 (all SMR releases prior to Feb-2026 Release 1)
• Samsung Android 16.0 (all SMR releases prior to Feb-2026 Release 1)

Discovery Timeline

• February 4, 2026 - CVE-2026-20978 published to NVD
• February 5, 2026 - Last updated in NVD database

Technical Details for CVE-2026-20978

Vulnerability Analysis

This vulnerability stems from improper authorization checks within the KnoxGuardManager component on Samsung Android devices. The flaw allows a local attacker with low-level privileges to circumvent the persistence configuration mechanisms that are designed to maintain security policies on managed devices.

The attack requires local access to the device, meaning an attacker would need physical access or the ability to execute code on the target device through another vector (such as a malicious application). While this limits the attack surface compared to remotely exploitable vulnerabilities, the impact on enterprise environments is significant, as it could allow managed devices to have their security configurations tampered with.

Successful exploitation primarily impacts the integrity of the device's security configuration, with potential for limited availability impact. Confidentiality is not directly affected according to the vulnerability characteristics.

Root Cause

The root cause of CVE-2026-20978 is insufficient authorization validation in the KnoxGuardManager component. The application fails to properly verify that requests to modify persistence configurations originate from authorized sources with appropriate privileges. This allows unprivileged local processes to interact with the component in ways that should be restricted to system-level or Knox management processes.

Attack Vector

The attack vector for this vulnerability is local, requiring the attacker to have existing access to the device. The exploitation process involves:

1. An attacker gains local access to a Samsung Android device (through physical access or via a malicious application)
2. The attacker interacts with the KnoxGuardManager component
3. Due to improper authorization checks, the attacker can send requests that bypass normal permission validation
4. The persistence configuration of KnoxGuardManager is modified or disabled
5. Enterprise security policies enforced by Knox may be circumvented

The vulnerability requires certain preconditions to be present for successful exploitation, and the attacker must have at least low-level privileges on the device. No user interaction is required for exploitation once the attacker has local access.

Detection Methods for CVE-2026-20978

Indicators of Compromise

• Unexpected modifications to Knox persistence configuration settings
• Anomalous activity or log entries related to KnoxGuardManager service
• Enterprise management policies becoming ineffective or disabled without authorized changes
• Unusual inter-process communication attempts targeting Knox components

Detection Strategies

• Monitor system logs for unauthorized access attempts to KnoxGuardManager APIs
• Implement application behavior monitoring to detect privilege escalation attempts targeting Knox components
• Deploy mobile threat defense solutions that can identify policy tampering on managed devices
• Audit Knox configuration state regularly against expected baseline configurations

Monitoring Recommendations

• Enable detailed logging for Knox components and enterprise management services
• Configure alerts for changes to device management policy enforcement status
• Monitor for applications requesting unusual permissions or exhibiting abnormal behavior patterns
• Implement endpoint detection and response (EDR) solutions for mobile devices in enterprise environments

How to Mitigate CVE-2026-20978

Immediate Actions Required

• Apply the Samsung Mobile Maintenance Release (SMR) Feb-2026 Release 1 update immediately
• Audit all Samsung Android devices in your environment to verify current patch levels
• Review Knox policy configurations on managed devices for any unauthorized modifications
• Implement additional device security monitoring until patches are deployed

Patch Information

Samsung has addressed this vulnerability in the SMR Feb-2026 Release 1 security update. The patch is available for Samsung Android versions 13.0, 14.0, 15.0, and 16.0. Organizations should deploy this update through their enterprise mobile device management (MDM) solution as a priority.

For detailed patch information, refer to the Samsung Mobile Security Update for February 2026.

Workarounds

• Restrict physical access to devices containing sensitive enterprise data
• Implement application allowlisting to prevent installation of potentially malicious applications
• Enable additional authentication requirements for Knox configuration changes where supported
• Consider network segmentation for managed devices until patches can be applied

# Verify device patch level via ADB
adb shell getprop ro.build.version.security_patch
# Expected output for patched devices: 2026-02-01 or later

# Check Knox version
adb shell getprop net.knoxvpn.version