---
id: CVE-2026-20502
title: 'In vdec, there is a possible out of bounds write due to a missing bounds check'
summary: >-
  In vdec, there is a possible out of bounds write due to a missing bounds
  check. This could lead to local escalation of privilege with no additional
  execution privileges needed. User interaction is not needed for exploitation.
  Patch ID: A…
severity: high
cvss: 8.4
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-122
vendor: mediatek
product: mt2718_firmware
affected:
  - mt2718_firmware
  - mt6580_firmware
  - mt6739_firmware
  - mt6761_firmware
  - mt6765_firmware
  - mt6768_firmware
  - mt6769_firmware
  - mt6779_firmware
  - mt6781_firmware
  - mt6785_firmware
  - mt6789_firmware
  - mt6833_firmware
  - mt6835_firmware
  - mt6853_firmware
  - mt6855_firmware
  - mt6858_firmware
  - mt6873_firmware
  - mt6877_firmware
  - mt6878_firmware
  - mt6879_firmware
  - mt6881_firmware
  - mt6883_firmware
  - mt6885_firmware
  - mt6886_firmware
  - mt6889_firmware
  - mt6893_firmware
  - mt6895_firmware
  - mt6897_firmware
  - mt6899_firmware
  - mt6983_firmware
  - mt6985_firmware
  - mt6989_firmware
  - mt6991_firmware
  - mt6993_firmware
  - mt8126_firmware
  - mt8171_firmware
  - mt8186_firmware
  - mt8188_firmware
  - mt8189_firmware
  - mt8195_firmware
  - mt8196_firmware
  - mt8367_firmware
  - mt8391_firmware
  - mt8395_firmware
  - mt8668_firmware
  - mt8676_firmware
  - mt8678_firmware
  - mt8696_firmware
  - mt8781_firmware
  - mt8788e_firmware
  - mt8792_firmware
  - mt8799_firmware
  - mt8910_firmware
published: '2026-09-07'
updated: '2026-09-09'
sourceUpdated: '2026-09-09T02:55:23.187'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-20502'
references:
  - url: 'https://www.mediatek.com/product-security-bulletin/September-2026'
    label: security@mediatek.com
tags:
  - nvd
  - cve.org
epss: 0.00128
epssPercentile: 0.02039
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-09-07T00:00:00+00:00'
ingestedAt: '2026-09-07T12:10:15.807Z'
---

## Overview

In vdec, there is a possible out of bounds write due to a missing bounds check. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation. Patch ID: ALPS11262030; Issue ID: MSV-9196.

## Affected

- `mt2718_firmware`
- `mt6580_firmware`
- `mt6739_firmware`
- `mt6761_firmware`
- `mt6765_firmware`
- `mt6768_firmware`
- `mt6769_firmware`
- `mt6779_firmware`
- `mt6781_firmware`
- `mt6785_firmware`
- `mt6789_firmware`
- `mt6833_firmware`
- `mt6835_firmware`
- `mt6853_firmware`
- `mt6855_firmware`
- `mt6858_firmware`
- `mt6873_firmware`
- `mt6877_firmware`
- `mt6878_firmware`
- `mt6879_firmware`
- `mt6881_firmware`
- `mt6883_firmware`
- `mt6885_firmware`
- `mt6886_firmware`
- `mt6889_firmware`
- `mt6893_firmware`
- `mt6895_firmware`
- `mt6897_firmware`
- `mt6899_firmware`
- `mt6983_firmware`
- `mt6985_firmware`
- `mt6989_firmware`
- `mt6991_firmware`
- `mt6993_firmware`
- `mt8126_firmware`
- `mt8171_firmware`
- `mt8186_firmware`
- `mt8188_firmware`
- `mt8189_firmware`
- `mt8195_firmware`
- `mt8196_firmware`
- `mt8367_firmware`
- `mt8391_firmware`
- `mt8395_firmware`
- `mt8668_firmware`
- `mt8676_firmware`
- `mt8678_firmware`
- `mt8696_firmware`
- `mt8781_firmware`
- `mt8788e_firmware`
- `mt8792_firmware`
- `mt8799_firmware`
- `mt8910_firmware`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.