CVE-2026-20516: MiracastService Privilege Escalation Flaw

CVE-2026-20516 Overview

CVE-2026-20516 is a privilege escalation vulnerability in the MediaTek MiracastService component. The flaw stems from a confused deputy condition [CWE-926], where an authorized component performs actions on behalf of an unauthorized caller. A local attacker with user-level execution privileges can trigger the flaw to cause a denial of service. User interaction is not required for exploitation. MediaTek tracks the issue as MSV-7882 and addresses it through patches ALPS11060069 and DTV04881615.

Critical Impact
A local application with user privileges can trigger a denial of service in the MiracastService component without any user interaction, disrupting Miracast wireless display functionality on affected MediaTek devices.

Affected Products

MediaTek chipsets shipping the MiracastService component
Android devices running affected MediaTek firmware
MediaTek DTV platforms (per patch ID DTV04881615)

Discovery Timeline

2026-09-07 - CVE-2026-20516 published to NVD
2026-09-08 - Last updated in NVD database

Technical Details for CVE-2026-20516

Vulnerability Analysis

The vulnerability resides in MediaTek's MiracastService, which handles wireless display streaming based on the Miracast standard. A confused deputy weakness [CWE-926] allows a low-privileged local application to leverage the service to perform actions it could not otherwise execute. The result is a high-availability impact with no confidentiality or integrity loss. Exploitation requires local access and user execution privileges but does not require any user interaction. The scope remains unchanged, meaning impact is confined to the vulnerable component's security domain.

Root Cause

The root cause is improper export or inadequate access control on an Android component within MiracastService. Confused deputy weaknesses arise when a privileged intermediary accepts requests without validating the origin's authority. In this case, MiracastService acts on inputs from unprivileged callers, allowing them to influence operations reserved for higher-privileged contexts and induce a service crash or resource exhaustion.

Attack Vector

An attacker must first install or run a low-privileged application on the target device. The application then issues crafted requests, likely through an exposed Android IPC surface such as an intent, binder call, or content provider, to the MiracastService. Because the service does not sufficiently validate the caller's permissions relative to the requested action, the request is honored and causes an availability failure. No physical access, network position, or user interaction is required.

See the MediaTek Product Security Bulletin for the vendor's technical description and patch references.

Detection Methods for CVE-2026-20516

Indicators of Compromise

Repeated unexpected crashes or restarts of the MiracastService process on MediaTek-based devices
logcat entries showing binder transaction failures or fatal exceptions originating from the MiracastService component
Unsigned or untrusted third-party applications invoking Miracast-related intents or binder interfaces

Detection Strategies

Monitor Android tombstone and dropbox records for crash signatures tied to the MiracastService process
Correlate installation events of unknown APKs with subsequent MiracastService failures
Baseline expected callers of Miracast IPC endpoints and alert on deviations

Monitoring Recommendations

Enroll MediaTek-based endpoints in a mobile device management platform that reports firmware patch level and crash telemetry
Ingest device logs into a centralized data lake for anomaly detection across the fleet
Track MediaTek Product Security Bulletin publications monthly to identify newly disclosed component-level issues

How to Mitigate CVE-2026-20516

Immediate Actions Required

Apply the vendor firmware update containing patch ALPS11060069 (mobile) or DTV04881615 (DTV) once your OEM releases it
Inventory MediaTek-based devices and identify those pending the September 2026 security patch level
Restrict installation of untrusted applications on affected devices through mobile device management policies

Patch Information

MediaTek assigned the fix to patch IDs ALPS11060069 and DTV04881615 under issue ID MSV-7882. Device OEMs must integrate the patch into their firmware images and deliver it through over-the-air updates. Consult the MediaTek Product Security Bulletin for September 2026 and your device manufacturer's advisory for availability.

Workarounds

Disable Miracast or wireless display features on affected devices where the functionality is not required
Enforce application allow-listing to prevent installation of untrusted local applications
Isolate high-value devices from workloads that permit sideloading until the patch is applied

bash

# Verify current Android security patch level on a MediaTek device
adb shell getprop ro.build.version.security_patch

# List installed packages to audit for untrusted applications
adb shell pm list packages -3