---
id: CVE-2026-20503
title: 'In Modem, there is a possible system crash due to a missing bounds check'
summary: >-
  In Modem, there is a possible system crash due to a missing bounds check. This
  could lead to remote denial of service, if a UE has connected to a rogue base
  station controlled by the attacker, with no additional execution privileges
  need…
severity: medium
cvss: 5.3
cvssVector: 'CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-617
vendor: mediatek
product: mt2716_firmware
affected:
  - mt2716_firmware
  - mt2735_firmware
  - mt2737_firmware
  - mt6813_firmware
  - mt6833_firmware
  - mt6835_firmware
  - mt6853_firmware
  - mt6855_firmware
  - mt6858_firmware
  - mt6873_firmware
  - mt6875_firmware
  - mt6877_firmware
  - mt6878_firmware
  - mt6879_firmware
  - mt6880_firmware
  - mt6881_firmware
  - mt6883_firmware
  - mt6885_firmware
  - mt6886_firmware
  - mt6889_firmware
  - mt6890_firmware
  - mt6891_firmware
  - mt6893_firmware
  - mt6895_firmware
  - mt6896_firmware
  - mt6897_firmware
  - mt6899_firmware
  - mt6980_firmware
  - mt6982vb_firmware
  - mt6983_firmware
  - mt6985_firmware
  - mt6986_firmware
  - mt6988_firmware
  - mt6989_firmware
  - mt6990_firmware
  - mt6991_firmware
  - mt6993_firmware
  - mt8668_firmware
  - mt8673_firmware
  - mt8675_firmware
  - mt8676_firmware
  - mt8678_firmware
  - mt8755_firmware
  - mt8771_firmware
  - mt8775_firmware
  - mt8791_firmware
  - mt8791t_firmware
  - mt8792_firmware
  - mt8793_firmware
  - mt8795t_firmware
  - mt8796_firmware
  - mt8797_firmware
  - mt8798_firmware
  - mt8863_firmware
  - mt8873_firmware
  - mt8883_firmware
  - mt8893_firmware
published: '2026-09-07'
updated: '2026-09-09'
sourceUpdated: '2026-09-09T02:55:29.153'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-20503'
references:
  - url: 'https://www.mediatek.com/product-security-bulletin/September-2026'
    label: security@mediatek.com
tags:
  - nvd
epss: 0.00192
epssPercentile: 0.09153
ingestedAt: '2026-09-07T12:10:15.852Z'
---

## Overview

In Modem, there is a possible system crash due to a missing bounds check. This could lead to remote denial of service, if a UE has connected to a rogue base station controlled by the attacker, with no additional execution privileges needed. User interaction is not needed for exploitation. Patch ID: MOLY01371002; Issue ID: MSV-9020.

## Affected

- `mt2716_firmware`
- `mt2735_firmware`
- `mt2737_firmware`
- `mt6813_firmware`
- `mt6833_firmware`
- `mt6835_firmware`
- `mt6853_firmware`
- `mt6855_firmware`
- `mt6858_firmware`
- `mt6873_firmware`
- `mt6875_firmware`
- `mt6877_firmware`
- `mt6878_firmware`
- `mt6879_firmware`
- `mt6880_firmware`
- `mt6881_firmware`
- `mt6883_firmware`
- `mt6885_firmware`
- `mt6886_firmware`
- `mt6889_firmware`
- `mt6890_firmware`
- `mt6891_firmware`
- `mt6893_firmware`
- `mt6895_firmware`
- `mt6896_firmware`
- `mt6897_firmware`
- `mt6899_firmware`
- `mt6980_firmware`
- `mt6982vb_firmware`
- `mt6983_firmware`
- `mt6985_firmware`
- `mt6986_firmware`
- `mt6988_firmware`
- `mt6989_firmware`
- `mt6990_firmware`
- `mt6991_firmware`
- `mt6993_firmware`
- `mt8668_firmware`
- `mt8673_firmware`
- `mt8675_firmware`
- `mt8676_firmware`
- `mt8678_firmware`
- `mt8755_firmware`
- `mt8771_firmware`
- `mt8775_firmware`
- `mt8791_firmware`
- `mt8791t_firmware`
- `mt8792_firmware`
- `mt8793_firmware`
- `mt8795t_firmware`
- `mt8796_firmware`
- `mt8797_firmware`
- `mt8798_firmware`
- `mt8863_firmware`
- `mt8873_firmware`
- `mt8883_firmware`
- `mt8893_firmware`

## Remediation

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