CVE-2026-21023: PackageManagerService Privilege Escalation

CVE-2026-21023 Overview

CVE-2026-21023 is an Insufficient Verification of Data Authenticity vulnerability affecting Samsung's PackageManagerService component. This security flaw exists in Samsung mobile devices running software versions prior to SMR Mar-2026 Release 1 and allows local attackers to modify the installation restriction of specific applications without proper authorization.

Critical Impact
Local attackers can bypass application installation restrictions, potentially allowing unauthorized software to be installed on affected Samsung devices.

Affected Products

Samsung Mobile Devices prior to SMR Mar-2026 Release 1
Samsung PackageManagerService component

Discovery Timeline

2026-04-29 - CVE CVE-2026-21023 published to NVD
2026-04-29 - Last updated in NVD database

Technical Details for CVE-2026-21023

Vulnerability Analysis

This vulnerability stems from insufficient verification of data authenticity within Samsung's PackageManagerService, a core Android component responsible for managing application installation, updates, and removal on Samsung devices. The flaw allows attackers with local access to manipulate the integrity of data used by the PackageManagerService to enforce installation restrictions.

When the PackageManagerService processes requests to modify application installation policies, it fails to properly validate the authenticity and origin of the data being used to make these decisions. This allows an attacker to craft malicious input that bypasses normal security controls, effectively circumventing the intended restrictions on which applications can be installed on the device.

Root Cause

The root cause of this vulnerability is the lack of proper data authenticity verification in the PackageManagerService component. The service does not adequately validate that the data controlling application installation restrictions originates from a trusted source or has not been tampered with. This missing verification step creates an opportunity for local attackers to inject or modify data that influences the service's behavior.

Attack Vector

This is a local attack vector vulnerability, meaning an attacker requires access to the device to exploit it. The attack does not require user interaction or elevated privileges. The attacker can modify installation restriction parameters through the vulnerable PackageManagerService interface, which processes the manipulated data without proper authenticity checks. This could enable the installation of potentially malicious applications that would normally be blocked by device policies.

The vulnerability mechanism involves manipulating the data integrity checks within the PackageManagerService. For detailed technical information, see the Samsung Security Update March 2026.

Detection Methods for CVE-2026-21023

Indicators of Compromise

Unexpected changes to application installation policies or restrictions on Samsung devices
Installation of applications that should have been blocked by existing device policies
Anomalous PackageManagerService log entries indicating policy modification attempts
Presence of unauthorized applications on devices with strict installation controls

Detection Strategies

Monitor PackageManagerService logs for unusual modification requests or policy changes
Implement Mobile Device Management (MDM) solutions to track and alert on installation policy modifications
Conduct regular audits of installed applications against approved application lists
Deploy endpoint detection tools capable of monitoring Samsung device security configurations

Monitoring Recommendations

Enable verbose logging for PackageManagerService operations where possible
Configure alerts for any changes to application installation restrictions
Implement continuous monitoring of device security posture through Samsung Knox or equivalent MDM solutions
Review device logs periodically for signs of exploitation attempts

How to Mitigate CVE-2026-21023

Immediate Actions Required

Update all affected Samsung devices to SMR Mar-2026 Release 1 or later
Review and audit current application installation policies on Samsung devices
Verify that no unauthorized applications have been installed on affected devices
Restrict physical access to sensitive devices until patches are applied

Patch Information

Samsung has addressed this vulnerability in the SMR Mar-2026 Release 1 security update. Organizations should prioritize deploying this update to all affected Samsung mobile devices. The official patch information is available through the Samsung Security Update March 2026.

Workarounds

Implement strict physical access controls for affected Samsung devices
Use Mobile Device Management (MDM) solutions to enforce additional application installation controls
Enable Samsung Knox security features to provide additional layers of protection
Monitor devices for unexpected application installations until the patch can be applied

bash

# Verify Samsung device software version via ADB
adb shell getprop ro.build.version.security_patch
# Expected output for patched devices: 2026-03-01 or later