CVE-2026-20495 Overview
CVE-2026-20495 is a local privilege escalation vulnerability in the MediaTek Bluetooth driver. The flaw stems from a missing permission check [CWE-862] that allows a local application with user-level execution privileges to bypass authorization controls. Exploitation does not require user interaction, making it viable for silent abuse by malicious applications already resident on the device. MediaTek addressed the issue under Patch ID WCNCR00488300 and Issue ID MSV-7296, published in the August 2026 MediaTek Product Security Bulletin.
Critical Impact
A local attacker with user-level privileges can escalate to elevated permissions on affected MediaTek-based devices without any user interaction.
Affected Products
- MediaTek Bluetooth driver (see MediaTek Product Security Bulletin for chipset coverage)
- Android devices incorporating vulnerable MediaTek Bluetooth components
- Downstream OEM firmware bundling the affected driver
Discovery Timeline
- 2026-08-03 - CVE-2026-20495 published to NVD
- 2026-08-05 - Last updated in NVD database
Technical Details for CVE-2026-20495
Vulnerability Analysis
The vulnerability resides in the MediaTek Bluetooth driver, where a code path exposes a privileged operation without validating the caller's permissions. A local application can invoke the affected interface and perform actions reserved for higher-privileged components. The result is a local escalation of privilege from a low-privilege user context to elevated system permissions on the device.
Because the flaw requires no user interaction, an installed application can trigger the code path silently. Attackers commonly chain such driver-level bypasses with remote application delivery to achieve persistent, elevated access on mobile endpoints.
Root Cause
The root cause is a missing authorization check [CWE-862] in the Bluetooth driver's interface handler. The driver dispatches a sensitive operation without verifying that the calling process holds the required permission. This design gap violates least-privilege enforcement at the kernel-driver boundary.
Attack Vector
The attack vector is local. An attacker delivers or installs a malicious application on the target device. The application issues a request to the vulnerable Bluetooth driver interface, bypassing the missing permission check and executing privileged functionality. No user prompt, click, or approval is required after the malicious app runs.
The vulnerability is described in prose only; no verified public exploit code is available. See the MediaTek Product Security Bulletin for vendor technical details.
Detection Methods for CVE-2026-20495
Indicators of Compromise
- Unexpected user-installed applications interacting with Bluetooth HAL or kernel driver interfaces.
- Processes running with elevated privileges that were spawned from unprivileged application contexts.
- Anomalous ioctl or binder calls targeting the MediaTek Bluetooth driver from non-system UIDs.
Detection Strategies
- Inventory devices for MediaTek chipsets and correlate against the August 2026 MediaTek bulletin patch level.
- Monitor Android security patch level (SPL) telemetry from MDM or EMM tooling to identify unpatched fleets.
- Hunt for privilege transitions in mobile EDR telemetry where a user-space app maps to a subsequent system-context action.
Monitoring Recommendations
- Track OEM firmware release notes for downstream inclusion of Patch ID WCNCR00488300.
- Alert on installations of sideloaded applications requesting Bluetooth permissions on unpatched devices.
- Aggregate mobile identification signals into a central data lake to correlate Bluetooth driver anomalies across the fleet.
How to Mitigate CVE-2026-20495
Immediate Actions Required
- Identify MediaTek-based devices in the fleet and confirm current Android security patch level.
- Apply the OEM firmware update that incorporates MediaTek Patch ID WCNCR00488300 as soon as it is released for each device model.
- Restrict sideloading and enforce application allowlisting on managed mobile endpoints until patches are deployed.
Patch Information
MediaTek published the fix in the August 2026 Product Security Bulletin under Patch ID WCNCR00488300 (Issue ID MSV-7296). Device manufacturers must integrate the patch into their firmware and distribute it through OTA updates. Confirm remediation by verifying the device security patch level matches or exceeds the August 2026 Android bulletin.
Workarounds
- Disable Bluetooth on affected devices when it is not required for business operations.
- Enforce MDM policies that block installation of untrusted applications on unpatched devices.
- Segment high-risk users to patched hardware until firmware updates are broadly available.
# Verify Android security patch level on a managed device
adb shell getprop ro.build.version.security_patch
# Expected output: 2026-08-01 or later
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
