CVE-2026-21057: Samsung Pass Privilege Escalation Flaw

CVE-2026-21057 Overview

CVE-2026-21057 is an improper input validation vulnerability in Samsung Pass prior to version 5.2.10.3. The flaw allows local privileged attackers to write out-of-bounds memory, corrupting adjacent data structures within the process. Samsung Pass is the credential and biometric authentication manager bundled on Samsung mobile devices, so successful exploitation impacts stored authentication material and application integrity. The vulnerability requires high privileges and local access, which limits opportunistic exploitation but remains relevant for privilege chains and malicious application scenarios.

Critical Impact
A local privileged attacker can trigger an out-of-bounds write in Samsung Pass, leading to memory corruption, potential code execution, and integrity loss for stored credentials.

Affected Products

Samsung Pass versions prior to 5.2.10.3
Samsung mobile devices with Samsung Pass installed
Android environments relying on Samsung Pass for credential storage

Discovery Timeline

2026-07-10 - CVE-2026-21057 published to the National Vulnerability Database (NVD)
2026-07-10 - Last updated in NVD database

Technical Details for CVE-2026-21057

Vulnerability Analysis

The vulnerability arises from improper input validation within Samsung Pass. When the application processes attacker-supplied input, it fails to enforce boundary checks before writing data into a memory buffer. This produces an out-of-bounds write [CWE-787] that corrupts memory adjacent to the intended destination. Because Samsung Pass handles authentication tokens, biometric-linked credentials, and autofill data, memory corruption inside its process directly threatens confidentiality of secrets and integrity of authentication flows. The CVSS vector indicates local attack vector with high privileges required and no user interaction, aligning with a scenario in which a privileged process or component on the device drives exploitation.

Root Cause

The root cause is missing or insufficient validation on the length or structure of input consumed by Samsung Pass before it is written to a fixed-size buffer. Without bounds enforcement, the write operation extends past the allocated region, overwriting neighboring memory. This class of defect is commonly categorized as Improper Input Validation leading to Out-of-Bounds Write.

Attack Vector

Exploitation requires local access to a Samsung device and elevated privileges. A malicious privileged process, or an attacker who has already obtained a privileged foothold on the device, delivers crafted input to Samsung Pass through its exposed interfaces. Processing the malformed input triggers the out-of-bounds write, allowing the attacker to corrupt process state. Depending on the corrupted structure, this can lead to arbitrary code execution within the Samsung Pass process context or manipulation of stored authentication material. No user interaction is required, and network exposure is not part of the attack path. Technical specifics beyond the advisory are not public; refer to the Samsung Mobile Security Update for vendor details.

Detection Methods for CVE-2026-21057

Indicators of Compromise

Unexpected crashes or tombstone entries referencing the Samsung Pass process on affected devices
Anomalous privileged application installations preceding Samsung Pass instability
Samsung Pass version reporting below 5.2.10.3 in device inventory

Detection Strategies

Inventory Samsung mobile endpoints and flag any device running Samsung Pass earlier than 5.2.10.3
Correlate Android crash logs and logcat output for repeated faults tied to the Samsung Pass package
Alert on installation of applications requesting elevated privileges alongside interaction with Samsung Pass components

Monitoring Recommendations

Enroll Samsung devices in a mobile device management (MDM) platform to track Samsung Pass build versions
Monitor for application sideloading and privilege escalation attempts on managed Android devices
Review Samsung security bulletins monthly and align patch verification with the vendor advisory cadence

How to Mitigate CVE-2026-21057

Immediate Actions Required

Update Samsung Pass to version 5.2.10.3 or later through the Galaxy Store as soon as the update is available
Apply the corresponding Samsung Mobile security patch level referenced in the July 2026 bulletin
Restrict installation of untrusted applications that could obtain the privileges needed to reach Samsung Pass interfaces

Patch Information

Samsung addressed the issue in Samsung Pass 5.2.10.3. Details are published in the Samsung Mobile Security Update for July 2026. Devices should apply both the Samsung Pass application update and the monthly device security patch.

Workarounds

Disable or uninstall Samsung Pass on devices where updating to 5.2.10.3 is not yet possible
Enforce MDM policies that block sideloaded or unverified applications on managed devices
Limit accounts and processes that hold elevated privileges on Samsung mobile endpoints

bash

# Configuration example: verify Samsung Pass version on a managed Android device via ADB
adb shell dumpsys package com.samsung.android.samsungpass | grep versionName
# Expected output should be 5.2.10.3 or higher after patching