What is CVE-2026-20478?

CVE-2026-20478 is a medium-severity vulnerability in Mediatek Mt2735 Firmware, classified under Out-of-bounds Write. CVSS score: 5.5/10. Published 2026-08-03.

How severe is CVE-2026-20478?

Medium severity. CVSS v3 base score is 5.5 out of 10.

Buffer overflow in Mediatek Mt2735 Firmware

CVE-2026-20478

In Audio HAL, there is a possible out of bounds write due to a heap buffer overflow. This could lead to local denial of service with User execution privileges needed. User interaction is not needed for exploitation. Patch ID: ALPS10981454 (Note: For MT6880, MT6890, MT6988, MT6990) / AUTO00851293 (Note: For MT2735, MT2737); Issue ID: MSV-7638.

Vulnerability class: Buffer Overflow

EPSS: 0.001 (1.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

Affected products

Mediatek Mt2735_firmware
Mediatek Mt2737_firmware
Mediatek Mt6880_firmware
Mediatek Mt6890_firmware
Mediatek Mt6988_firmware
Mediatek Mt6990_firmware
Mediatek, Inc. Mediatek Chipset — versions MT2735, MT2737, MT6880

Weakness classification (CWE)

CWE-787 — Out-of-bounds Write

References

security@mediatek.com (Vendor Advisory)

Frequently asked questions

What is CVE-2026-20478?: CVE-2026-20478 is a medium-severity vulnerability in Mediatek Mt2735 Firmware, classified under Out-of-bounds Write. CVSS score: 5.5/10. Published 2026-08-03.
How severe is CVE-2026-20478?: Medium severity. CVSS v3 base score is 5.5 out of 10.