CVE-2026-21044: KnoxGuardManager Auth Bypass Vulnerability

CVE-2026-21044 Overview

CVE-2026-21044 is an improper authorization vulnerability in Samsung's KnoxGuardManager component. The flaw exists in Samsung mobile devices prior to the Security Maintenance Release (SMR) Jul-2026 Release 1. A local attacker can exploit this weakness to bypass the persistence configuration of the application. Samsung addressed the issue in its July 2026 monthly security update.

The vulnerability requires local access and low privileges, and does not require user interaction. Successful exploitation impacts the integrity of the affected device while leaving confidentiality unaffected. Samsung published the fix through its regular mobile security update cycle.

Critical Impact
Local attackers with low privileges can bypass KnoxGuardManager persistence controls, undermining device management integrity on unpatched Samsung mobile devices.

Affected Products

Samsung Mobile devices running KnoxGuardManager prior to SMR Jul-2026 Release 1
Samsung Galaxy devices receiving the Samsung Mobile monthly Security Maintenance Release (SMR)
Any Samsung Android build shipped before the July 2026 SMR patch level

Discovery Timeline

2026-07-10 - CVE-2026-21044 published to the National Vulnerability Database (NVD)
2026-07-10 - Samsung releases the July 2026 SMR with the fix
2026-07-10 - Last updated in NVD database

Technical Details for CVE-2026-21044

Vulnerability Analysis

CVE-2026-21044 stems from an improper authorization check within Samsung's KnoxGuardManager. KnoxGuardManager is part of the Knox platform used by carriers and enterprises to enforce device policies, including persistence settings that keep the management application resident on the device.

The vulnerability allows a local, low-privileged actor to bypass authorization checks that gate the persistence configuration. By circumventing these checks, an attacker can alter behavior that is intended to be enforced by the trusted management layer. The classification aligns with [CWE-285: Improper Authorization].

The issue is a device-integrity concern rather than a data-exposure concern. The CVSS assessment reflects a high integrity impact with no confidentiality impact and limited availability effect. The EPSS probability for exploitation is 0.096%.

Root Cause

The root cause is a missing or insufficient authorization check inside KnoxGuardManager when the persistence configuration is modified. The component fails to validate whether the calling context is authorized to change that configuration. This lets an unprivileged local caller reach code paths reserved for privileged management flows.

Attack Vector

Exploitation requires local access to the device, for example through an installed application or an on-device shell context. The attacker leverages an interface exposed by KnoxGuardManager and invokes the persistence configuration path without holding the required authorization. No user interaction is needed. Because the attack vector is local, remote exploitation over the network is not applicable.

No public proof-of-concept code has been published. Samsung has not disclosed exploitation in the wild, and the vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog. Technical specifics are limited to the vendor advisory referenced in the Samsung Mobile Security Update.

Detection Methods for CVE-2026-21044

Indicators of Compromise

Samsung devices reporting a security patch level earlier than 2026-07-01 in enterprise inventory
Unexpected changes to KnoxGuardManager persistence settings on managed Samsung devices
Local applications invoking KnoxGuardManager interfaces outside of approved management workflows

Detection Strategies

Query mobile device management (MDM) or unified endpoint management (UEM) inventories for Samsung devices below SMR Jul-2026 Release 1
Correlate Knox attestation results with expected policy state to identify devices whose persistence configuration diverges from policy
Review application install telemetry for untrusted apps requesting access to Knox-related components

Monitoring Recommendations

Monitor Samsung SMR patch-level compliance across the fleet and alert on devices lagging the July 2026 baseline
Track Knox policy drift events and management-agent removal or reinstallation attempts
Ingest Samsung security bulletin feeds into vulnerability management to detect newly affected models

How to Mitigate CVE-2026-21044

Immediate Actions Required

Apply the Samsung SMR Jul-2026 Release 1 update on all affected Samsung mobile devices
Enforce a minimum security patch level of 2026-07-01 through MDM compliance rules
Restrict installation of untrusted applications on managed Samsung devices

Patch Information

Samsung addressed CVE-2026-21044 in the SMR Jul-2026 Release 1 update. The vendor advisory and full list of affected models are available in the Samsung Mobile Security Update. Administrators should push the July 2026 firmware to all Galaxy devices and confirm the applied patch level through device attestation.

Workarounds

No vendor-supplied workaround is documented; patching is the required remediation
Limit device access to trusted users and applications until the SMR Jul-2026 update is installed
Use MDM conditional access to block non-compliant Samsung devices from sensitive resources

bash

# Verify Samsung security patch level via adb
adb shell getprop ro.build.version.security_patch
# Expected output for patched devices: 2026-07-01 or later