CVE-2026-21002: Galaxy Store Auth Bypass Vulnerability

CVE-2026-21002 Overview

CVE-2026-21002 is a cryptographic signature verification vulnerability affecting Samsung Galaxy Store prior to version 4.6.03.8. The flaw allows a local attacker to bypass application signature verification, enabling the installation of arbitrary applications on affected Samsung devices. This represents a significant security concern for mobile device integrity and user data protection.

Critical Impact

Local attackers can exploit improper cryptographic signature verification to install malicious applications, potentially compromising device integrity and user data on affected Samsung devices.

Affected Products

• Samsung Galaxy Store versions prior to 4.6.03.8
• Samsung mobile devices running vulnerable Galaxy Store versions

Discovery Timeline

• March 16, 2026 - CVE-2026-21002 published to NVD
• March 16, 2026 - Last updated in NVD database

Technical Details for CVE-2026-21002

Vulnerability Analysis

This vulnerability stems from improper verification of cryptographic signatures within the Samsung Galaxy Store application. The signature verification mechanism, which is designed to ensure that only legitimate and authorized applications can be installed, fails to properly validate application packages. This weakness allows an attacker with local access to the device to install arbitrary applications that would normally be rejected by the security checks.

The local attack vector requires the attacker to have some level of access to the target device, either through physical proximity, another compromised application, or social engineering. Once this access is obtained, the attacker can leverage the cryptographic verification weakness to sideload malicious applications that appear to be legitimate.

Root Cause

The root cause of CVE-2026-21002 lies in the improper implementation of cryptographic signature verification within the Galaxy Store's application installation pipeline. The verification routine fails to adequately validate the integrity and authenticity of application signatures, creating a gap that allows unsigned or improperly signed applications to pass through security checks.

This type of vulnerability typically occurs when:

• Signature validation checks are incomplete or can be bypassed
• The verification logic contains flaws in how it processes certificate chains
• Error handling during verification fails to properly reject invalid signatures

Attack Vector

The attack requires local access to the target Samsung device. An attacker exploiting this vulnerability would need to:

1. Gain local access to the target Samsung device through physical access, ADB connection, or another compromised application
2. Prepare a malicious application package designed to exploit the signature verification flaw
3. Trigger the Galaxy Store's installation routine with the crafted package
4. Bypass the cryptographic signature verification to successfully install the malicious application

The exploitation does not require any user interaction once the attacker has local access, and no special privileges are needed to execute the attack. The primary impact is on system integrity, as unauthorized applications can be installed on the device.

Detection Methods for CVE-2026-21002

Indicators of Compromise

• Unexpected applications installed on Samsung devices that were not downloaded through official channels
• Galaxy Store logs showing unusual installation activities or verification errors
• Applications with missing or invalid signatures present on the device
• Anomalous process behavior from recently installed applications

Detection Strategies

• Monitor Galaxy Store application logs for signature verification failures or bypass attempts
• Implement mobile device management (MDM) solutions to track application installations
• Use endpoint detection and response (EDR) solutions capable of monitoring mobile application behavior
• Conduct periodic application inventory audits to identify unauthorized installations

Monitoring Recommendations

• Enable comprehensive logging for application installation events on managed Samsung devices
• Configure alerts for any applications installed outside of standard enterprise deployment channels
• Monitor for network traffic anomalies from recently installed applications
• Implement application whitelisting policies through MDM solutions where feasible

How to Mitigate CVE-2026-21002

Immediate Actions Required

• Update Samsung Galaxy Store to version 4.6.03.8 or later immediately
• Review recently installed applications on affected devices for any unauthorized software
• Restrict physical access to sensitive devices until patching is complete
• Consider temporarily disabling application installation capabilities on high-risk devices

Patch Information

Samsung has released a security update addressing this vulnerability. Users and administrators should update the Galaxy Store application to version 4.6.03.8 or later. The patch is available through the Samsung Mobile Security Update portal.

For enterprise environments, administrators should prioritize deployment of this update through their mobile device management infrastructure. The update resolves the improper cryptographic signature verification by implementing proper validation checks within the application installation pipeline.

Workarounds

• Implement strict physical access controls for Samsung devices pending the update
• Use mobile device management (MDM) to restrict application installation sources
• Enable enhanced security features such as Knox security policies on enterprise devices
• Monitor device logs for any suspicious installation activity until the patch is applied
• Consider network segmentation for devices that cannot be immediately patched