CVE-2026-21016: Samsung Android Privilege Escalation Flaw

CVE-2026-21016 Overview

CVE-2026-21016 is an incorrect privilege assignment vulnerability in the LocationManager component of Samsung Android. The flaw affects Samsung Android versions 14.0, 15.0, and 16.0 prior to the Samsung Mobile Release (SMR) May-2026 Release 1 security update. A local attacker with code execution on the device can leverage the improper privilege assignment to access sensitive information that should be protected by Android's permission model.

Samsung published the corresponding security maintenance release through its mobile security advisory portal. The issue is categorized under [NVD-CWE-Other] and does not require user interaction or elevated privileges to exploit.

Critical Impact

Local applications on unpatched Samsung Android devices can bypass the intended permission boundary of LocationManager to read sensitive information, including location-related data, without holding the required privileges.

Affected Products

• Samsung Android 14.0 (prior to SMR May-2026 Release 1)
• Samsung Android 15.0 (prior to SMR May-2026 Release 1)
• Samsung Android 16.0 (prior to SMR May-2026 Release 1)

Discovery Timeline

• 2026-05-13 - CVE-2026-21016 published to NVD
• 2026-05-13 - Samsung publishes SMR May-2026 Release 1 advisory
• 2026-05-13 - Last updated in NVD database

Technical Details for CVE-2026-21016

Vulnerability Analysis

The vulnerability resides in Samsung's customized LocationManager service, a system-level component that brokers access to location data and related services on Android devices. Samsung's implementation extends the Android Open Source Project (AOSP) LocationManager with proprietary functionality. The flaw is an incorrect privilege assignment, meaning a code path within the service grants callers more privilege than the security model intends.

An unprivileged local application can interact with the affected interface and receive sensitive information that should otherwise be gated behind runtime permissions or system-level access. The disclosure scope is limited to information exposure, with low integrity and availability impact and no cross-system reach.

Root Cause

The root cause is improper privilege assignment within LocationManager prior to SMR May-2026 Release 1. The service does not correctly enforce the privilege required to access certain operations or data. Calls that should be restricted to system or signature-level callers are reachable from lower-privileged contexts. Samsung addressed the defect by tightening the privilege checks in the May 2026 maintenance release.

Attack Vector

Exploitation requires local access. An attacker must run code on the target device, typically through a malicious or compromised application installed by the user. No user interaction or prior authentication is required once the malicious app is running. The application invokes the exposed LocationManager functionality from its own process context and retrieves sensitive data it would not normally be allowed to read.

No public proof-of-concept exploit, ExploitDB entry, or evidence of in-the-wild exploitation has been associated with CVE-2026-21016. The vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog.

Detection Methods for CVE-2026-21016

Indicators of Compromise

• Installed third-party applications that repeatedly query LocationManager APIs without declaring the corresponding location permissions in their manifest.
• Unexpected access to location-related data by applications that have no business need for geolocation functionality.
• Devices running Samsung Android 14.0, 15.0, or 16.0 at a patch level older than SMR May-2026 Release 1.

Detection Strategies

• Inventory Samsung Android devices in mobile fleets and compare the reported security patch level against SMR May-2026 Release 1.
• Review installed application manifests for missing ACCESS_FINE_LOCATION or ACCESS_COARSE_LOCATION declarations paired with runtime calls to LocationManager.
• Use mobile threat defense or enterprise mobility management (EMM) tooling to flag applications exhibiting anomalous location service invocations.

Monitoring Recommendations

• Monitor application behavior logs from managed Samsung devices for unusual access to system services.
• Track Samsung security advisory updates at the Samsung Mobile Security Update portal and align patch verification accordingly.
• Alert on Samsung devices that remain below the May 2026 SMR patch level beyond a defined remediation window.

How to Mitigate CVE-2026-21016

Immediate Actions Required

• Apply Samsung's SMR May-2026 Release 1 update on all affected Samsung Android 14.0, 15.0, and 16.0 devices.
• Verify the security patch level on managed endpoints through EMM or mobile device management (MDM) consoles.
• Restrict installation of unvetted third-party applications on corporate devices until patching is confirmed.

Patch Information

Samsung released the fix in the SMR May-2026 Release 1 security maintenance update. Details are available in the Samsung Mobile Security Update advisory. Devices report compliance through the Android security patch level string exposed under Settings → About phone → Software information.

Workarounds

• Limit application installations to vetted sources such as Galaxy Store and Google Play, and enforce this through MDM policy.
• Audit and remove applications that request or invoke location services without a clear business justification.
• Where business policy permits, disable system-level location services on high-risk devices until the patch is deployed.

# Verify Samsung Android security patch level on a managed device via ADB
adb shell getprop ro.build.version.security_patch
# Expected value on patched devices: 2026-05-01 or later