CVE-2026-20480 Overview
CVE-2026-20480 is a heap buffer overflow vulnerability in the MediaTek Audio Hardware Abstraction Layer (HAL). The flaw allows an out-of-bounds write on the heap, which can cause a local denial of service. Exploitation requires local access with user-level execution privileges but does not require user interaction. The issue is tracked internally by MediaTek as MSV-7586 and is addressed by patch IDs ALPS10960023 and AUTO00851189. Affected chipsets include MT6880, MT6890, MT6980D, MT6988, MT6990, MT2735, and MT3737. The vulnerability is classified under [CWE-122] Heap-based Buffer Overflow.
Critical Impact
An authenticated local attacker can trigger a heap-based out-of-bounds write in the Audio HAL, resulting in denial of service on affected MediaTek chipsets used in mobile and automotive platforms.
Affected Products
- MediaTek chipsets MT6880, MT6890, MT6980D, MT6988, MT6990 (patch ALPS10960023)
- MediaTek automotive chipsets MT2735, MT3737 (patch AUTO00851189)
- Devices integrating MediaTek Audio HAL components on the above SoCs
Discovery Timeline
- 2026-08-03 - CVE-2026-20480 published to NVD
- 2026-08-03 - Last updated in NVD database
- August 2026 - Disclosed in the MediaTek Security Bulletin August 2026
Technical Details for CVE-2026-20480
Vulnerability Analysis
The vulnerability resides in the Audio HAL, the userspace component that mediates between Android audio framework services and the underlying MediaTek audio hardware. A heap buffer overflow condition allows a caller with local user privileges to write beyond the bounds of a heap-allocated buffer. The write corrupts adjacent heap metadata or object state within the audio service process.
Because the CVSS vector indicates no impact on confidentiality or integrity but high impact on availability, the practical outcome is a crash of the audio service or associated process. Exploitation does not require user interaction, and the attack surface is limited to processes able to invoke Audio HAL interfaces on the device.
Root Cause
The root cause is missing or insufficient bounds validation on data supplied to an Audio HAL routine that writes to a heap buffer. The condition is a classic heap-based out-of-bounds write [CWE-122]. Specific function names and code paths are not disclosed in the public advisory. See the MediaTek Security Bulletin August 2026 for vendor-supplied technical detail.
Attack Vector
An attacker requires local code execution with low privileges on the target device, such as an installed application or a compromised low-privilege process. The attacker crafts input to an Audio HAL entry point that triggers the out-of-bounds write. No user interaction is required. The impact is confined to denial of service on the affected chipset.
No public proof-of-concept exploit is available for CVE-2026-20480, and it is not listed in the CISA Known Exploited Vulnerabilities catalog. Refer to the vendor bulletin for technical details.
Detection Methods for CVE-2026-20480
Indicators of Compromise
- Repeated crashes or restarts of the Android audio service (audioserver) or MediaTek Audio HAL processes on affected chipsets
- Kernel or tombstone logs referencing heap corruption within Audio HAL libraries
- Unexpected loss of audio functionality following execution of untrusted local applications
Detection Strategies
- Monitor device crash reporting telemetry for signal SIGSEGV or SIGABRT faults originating in Audio HAL modules on MediaTek platforms
- Review installed applications on affected devices for those making unusual or high-frequency calls to audio subsystem interfaces
- Correlate audio service restarts with recently installed or updated applications during triage
Monitoring Recommendations
- Ingest Android logcat and tombstone output into a centralized logging platform for fleet-wide crash analytics
- Track firmware and patch levels across managed mobile and automotive devices to identify unpatched MediaTek SoCs
- Alert on abnormal reboots or audio subsystem failures on fleets that include MT6880, MT6890, MT6980D, MT6988, MT6990, MT2735, or MT3737
How to Mitigate CVE-2026-20480
Immediate Actions Required
- Apply the MediaTek patches ALPS10960023 and AUTO00851189 through the device OEM's firmware update channel as soon as they are available
- Inventory devices running affected MediaTek chipsets and prioritize patching for automotive and high-availability deployments
- Restrict installation of untrusted third-party applications on affected devices until patches are deployed
Patch Information
MediaTek released fixes referenced by patch IDs ALPS10960023 (for MT6880, MT6890, MT6980D, MT6988, MT6990) and AUTO00851189 (for MT2735, MT3737) under Issue ID MSV-7586. Distribution occurs through device OEMs and their over-the-air update programs. See the MediaTek Security Bulletin August 2026 for the authoritative fix references.
Workarounds
- Limit device access to trusted users and enforce application allow-listing via mobile device management (MDM)
- Disable or restrict local execution paths that expose Audio HAL interfaces to untrusted callers where OEM configuration permits
- Monitor for repeated audio service crashes and investigate the originating application when observed
# Example: check Android security patch level on a managed device
adb shell getprop ro.build.version.security_patch
adb shell getprop ro.vendor.mediatek.version.release
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
