MediaTek Audio HAL CVE-2026-20507

Exploitation requires the attacker to already possess System-level privilege on the target MediaTek device - this is a non-trivial prerequisite in the Android security model, typically requiring a prior exploit chain. Local device access is mandatory (AV:L); no network-based or remote exploitation path is described. No user interaction is required once System privilege is held. The vulnerability is specific to MediaTek chipsets listed above running the vulnerable Audio HAL version; devices not using affected MediaTek SoCs are not impacted. No special Audio HAL configuration or non-default feature is described as required.

The provided CVSS 3.1 score of 6.7 with vector AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H accurately captures the constrained exploitability: the attacker must already hold System-level privilege on the target device, limiting the initial entry bar significantly. In the Android security model, a System privilege pre-condition means the attacker has likely already exploited a separate vulnerability - this CVE would form a second stage in a privilege escalation chain, not a standalone entry point. The C:H/I:H/A:H impact triad is realistic for a UAF-to-code-execution scenario. No KEV listing and no POC are identified, and the EPSS signal is not provided in source data. Real-world priority should be elevated for devices in regulated or enterprise Android deployments where full firmware integrity is critical, but for consumer threat models the prerequisite System privilege lowers urgency considerably. The massive chipset coverage (65+ models) means patch distribution coverage across OEM and carrier supply chains will be uneven - patched MediaTek-provided firmware may not reach end devices without separate OEM and carrier updates.

An attacker who has already compromised a system-privileged process on a MediaTek-based Android device - for example by chaining an app vulnerability with a previous System-level exploit - triggers the use-after-free in the Audio HAL by causing the HAL to access a previously freed audio buffer during a concurrent audio session. By controlling the freed memory's contents through heap manipulation (heap spray or allocation timing), the attacker redirects execution flow to achieve arbitrary code execution at a higher privilege level, such as the kernel or a TEE-adjacent context.