CVE-2026-21075: My Galaxy Information Disclosure Flaw

CVE-2026-21075 Overview

CVE-2026-21075 is an improper authorization vulnerability in the custom URL scheme handler of Samsung's My Galaxy application. Versions prior to 6.3 fail to properly authorize requests received through the registered URL scheme. Remote attackers can leverage this weakness to access sensitive information from the application. The flaw is categorized under CWE-939, Improper Authorization in Handler for Custom URL Scheme. Exploitation requires user interaction, typically through a crafted link that triggers the vulnerable handler in the mobile browser or another application.

Critical Impact
Remote attackers can access sensitive information stored or processed by the My Galaxy application by inducing a user to interact with a malicious custom URL scheme link.

Affected Products

Samsung My Galaxy application versions prior to 6.3
Android devices with vulnerable My Galaxy installed
Samsung Mobile ecosystem components consuming the My Galaxy URL scheme

Discovery Timeline

2026-08-10 - CVE-2026-21075 published to NVD
2026-08-10 - Last updated in NVD database

Technical Details for CVE-2026-21075

Vulnerability Analysis

The My Galaxy application registers a custom URL scheme on Android to receive deep links from browsers and other applications. The handler that processes these inbound URIs does not adequately verify the origin or authorization of the caller. As a result, any application or web page capable of launching a URI can invoke privileged functionality within My Galaxy.

The vulnerability aligns with CWE-939, which describes mobile applications that trust arbitrary callers to a custom URL scheme. Because the Android URI dispatch mechanism does not inherently authenticate the source of an intent, applications must independently enforce authorization on scheme parameters. My Galaxy versions prior to 6.3 skip or insufficiently perform this check.

Root Cause

The root cause is missing authorization logic in the code path that parses and acts on incoming custom URL scheme requests. The handler treats externally supplied URI parameters as trusted, permitting access to internal endpoints that expose sensitive user information. The confidentiality impact is limited to low-value data according to the CVSS vector, but no privileges are required from the attacker's side.

Attack Vector

An attacker hosts a malicious web page or delivers a crafted message containing a link that uses the My Galaxy custom URL scheme. When the victim taps the link, Android routes the request to My Galaxy, which processes the parameters without authorization checks. The handler then returns or exposes sensitive information. Exploitation is remote over the network, requires no authentication, and depends on user interaction (UI:P).

No verified proof-of-concept code is publicly available. Refer to the Samsung Mobile Security Advisory for vendor-supplied technical detail.

Detection Methods for CVE-2026-21075

Indicators of Compromise

Outbound clicks or referrer traffic originating from unfamiliar domains that construct My Galaxy custom URL scheme links.
Unexpected launches of the My Galaxy application immediately following browser navigation or messaging app interaction.
Mobile telemetry showing intent dispatch to My Galaxy from non-Samsung origin packages.

Detection Strategies

Inventory Samsung mobile devices to identify installations of My Galaxy at versions below 6.3.
Inspect mobile threat defense logs for deep-link invocations targeting Samsung custom URL schemes from external sources.
Correlate web proxy logs against domains that embed Samsung custom URL scheme URIs in HTML anchors or JavaScript redirects.

Monitoring Recommendations

Enable mobile application telemetry on managed devices to capture intent activity and URI handler invocations.
Alert on repeated launches of My Galaxy triggered by external applications or browsers within short time windows.
Track patch compliance for My Galaxy across the mobile fleet through unified endpoint management reporting.

How to Mitigate CVE-2026-21075

Immediate Actions Required

Update My Galaxy to version 6.3 or later on all affected Samsung Android devices.
Push the update through mobile device management to enforce compliance across the fleet.
Advise users to avoid tapping unsolicited links that could invoke Samsung custom URL schemes.

Patch Information

Samsung addressed the improper authorization defect in My Galaxy version 6.3. Details are published in the Samsung Mobile Security Advisory for August 2026. Administrators should verify that managed devices receive the updated package from the Galaxy Store.

Workarounds

Restrict installation of My Galaxy on enterprise-managed devices until the update to version 6.3 is applied.
Configure mobile browsers to prompt before launching external applications through custom URL schemes.
Educate users to validate the source of any link that opens Samsung applications automatically.

bash

# Verify installed My Galaxy version on a managed Android device via ADB
adb shell dumpsys package com.samsung.android.voc | grep versionName

# Trigger an update check through the Galaxy Store
adb shell am start -a android.intent.action.VIEW \
  -d "samsungapps://ProductDetail/com.samsung.android.voc"