CVE-2026-21074 Overview
CVE-2026-21074 is a local privilege escalation vulnerability in Samsung's Bixby virtual assistant. Incorrect default permissions in Bixby prior to version 4.0.86.0 allow local attackers to execute arbitrary commands with Bixby privilege. The flaw is classified as [CWE-276] Incorrect Default Permissions. Samsung addressed the issue in its August 2026 Mobile Security Update. Local access to the device is required for exploitation, but user interaction is not.
Critical Impact
Local attackers can execute arbitrary commands under the Bixby process context, exposing sensitive assistant data and enabling further device compromise.
Affected Products
- Samsung Bixby versions prior to 4.0.86.0
- Samsung mobile devices with Bixby preinstalled
- Android platforms shipping Bixby as a system application
Discovery Timeline
- 2026-08-10 - CVE-2026-21074 published to NVD
- 2026-08-11 - Last updated in NVD database
Technical Details for CVE-2026-21074
Vulnerability Analysis
The vulnerability originates from insecure default permissions assigned to Bixby components on Samsung devices. A local attacker with limited privileges can interact with these components and issue commands that execute within the Bixby process context. Because Bixby runs as a privileged system service on Samsung devices, arbitrary command execution provides access to resources normally restricted to system-level applications. Exploitation requires local access and low privileges, but no user interaction. The scope is bounded to the Bixby subsystem, yet the confidentiality and integrity impact within that boundary is high.
Root Cause
The root cause is [CWE-276] Incorrect Default Permissions. Bixby ships components with permissions that do not enforce the principle of least privilege. Unprivileged local processes can reach interfaces intended to be internal, bypassing the intended access boundary between third-party applications and the Bixby service.
Attack Vector
The attack vector is local. An attacker must first place code on the device, typically via a malicious application installed by the user or a compromised third-party app. The malicious code then invokes the misconfigured Bixby interface to run commands with Bixby privilege. No credentials or user interaction are required beyond the initial installation of the attacker-controlled application. No public proof-of-concept exploit or verified code sample is available. Refer to the Samsung Mobile Security Update for technical details.
Detection Methods for CVE-2026-21074
Indicators of Compromise
- Installation of untrusted or sideloaded applications that request access to Bixby components or intents.
- Unexpected Bixby process activity, including command execution or file writes outside typical assistant behavior.
- Log entries showing inter-process communication from non-system UIDs to Bixby interfaces.
Detection Strategies
- Inventory mobile devices to identify Samsung handsets running Bixby versions prior to 4.0.86.0.
- Monitor mobile device management (MDM) telemetry for applications interacting with Bixby components.
- Correlate application installation events with anomalous privilege-context behavior on affected devices.
Monitoring Recommendations
- Enable mobile threat defense on managed Samsung devices to flag suspicious local application activity.
- Forward mobile security logs into a centralized data lake for retrospective analysis against Bixby-related indicators.
- Alert on installations of applications from unknown sources on devices that have not applied the August 2026 Samsung patch.
How to Mitigate CVE-2026-21074
Immediate Actions Required
- Apply the Samsung August 2026 Mobile Security Update to upgrade Bixby to version 4.0.86.0 or later.
- Enforce MDM policies that block installation of applications from untrusted sources on Samsung devices.
- Audit installed applications on affected devices and remove any that are unknown, unnecessary, or untrusted.
Patch Information
Samsung released a fix in the August 2026 Mobile Security Update, which raises Bixby to version 4.0.86.0. Details are available in the Samsung Mobile Security Update advisory. Users should apply the patch through system updates as soon as it is available for their device model and carrier.
Workarounds
- Disable Bixby on affected devices where operationally feasible until the patch is applied.
- Restrict device usage to trusted applications through enterprise application allowlisting.
- Educate users to avoid sideloading applications from outside Google Play or the Galaxy Store.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
