CVE-2026-20459

Modem Firmware Improper Input Validation Enables Remote Denial of Service

Published Jul 1, 2026 CVSS 3.1 · 5.3 Medium EPSS < 1% KEV · Not listed

Description

In Modem, there is a possible system crash due to improper input validation. 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: MOLY01816800; Issue ID: MSV-6842.

Affected Products

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

MediaTek, Inc.

MediaTek chipset

unaffected

Version	Status	Constraints
`MT2716`	affected	—
`MT2735`	affected	—
`MT2737`	affected	—
`MT6739`	affected	—
`MT6761`	affected	—
`MT6762`	affected	—
`MT6763`	affected	—
`MT6765`	affected	—
`MT6767`	affected	—
`MT6768`	affected	—
`MT6769`	affected	—
`MT6771`	affected	—
`MT6779`	affected	—
`MT6781`	affected	—
`MT6783`	affected	—
`MT6785`	affected	—
`MT6789`	affected	—
`MT6813`	affected	—
`MT6833`	affected	—
`MT6835`	affected	—
`MT6853`	affected	—
`MT6855`	affected	—
`MT6858`	affected	—
`MT6873`	affected	—
`MT6875`	affected	—
`MT6877`	affected	—
`MT6878`	affected	—
`MT6879`	affected	—
`MT6880`	affected	—
`MT6881`	affected	—
`MT6883`	affected	—
`MT6885`	affected	—
`MT6886`	affected	—
`MT6889`	affected	—
`MT6890`	affected	—
`MT6891`	affected	—
`MT6893`	affected	—
`MT6895`	affected	—
`MT6896`	affected	—
`MT6897`	affected	—
`MT6899`	affected	—
`MT6980`	affected	—
`MT6982`	affected	—
`MT6983`	affected	—
`MT6985`	affected	—
`MT6986`	affected	—
`MT6986D`	affected	—
`MT6988`	affected	—
`MT6989`	affected	—
`MT6990`	affected	—
`MT6991`	affected	—
`MT6993`	affected	—
`MT8666`	affected	—
`MT8667`	affected	—
`MT8668`	affected	—
`MT8673`	affected	—
`MT8675`	affected	—
`MT8676`	affected	—
`MT8678`	affected	—
`MT8755`	affected	—
`MT8765`	affected	—
`MT8766`	affected	—
`MT8766R`	affected	—
`MT8768`	affected	—
`MT8771`	affected	—
`MT8775`	affected	—
`MT8781`	affected	—
`MT8786`	affected	—
`MT8788`	affected	—
`MT8788E`	affected	—
`MT8789`	affected	—
`MT8791`	affected	—
`MT8791T`	affected	—
`MT8792`	affected	—
`MT8793`	affected	—
`MT8795T`	affected	—
`MT8796`	affected	—
`MT8797`	affected	—
`MT8798`	affected	—
`MT8863`	affected	—
`MT8873`	affected	—
`MT8883`	affected	—
`MT8893`	affected	—

No data.

Vendor Product Versions

Mediatek, Inc.

Mediatek Chipset

Version	Status	Scheme	Platform
`MT2716`	affected	generic	—
`MT2735`	affected	generic	—
`MT2737`	affected	generic	—
`MT6739`	affected	generic	—
`MT6761`	affected	generic	—
`MT6762`	affected	generic	—
`MT6763`	affected	generic	—
`MT6765`	affected	generic	—
`MT6767`	affected	generic	—
`MT6768`	affected	generic	—
`MT6769`	affected	generic	—
`MT6771`	affected	generic	—
`MT6779`	affected	generic	—
`MT6781`	affected	generic	—
`MT6783`	affected	generic	—
`MT6785`	affected	generic	—
`MT6789`	affected	generic	—
`MT6813`	affected	generic	—
`MT6833`	affected	generic	—
`MT6835`	affected	generic	—
`MT6853`	affected	generic	—
`MT6855`	affected	generic	—
`MT6858`	affected	generic	—
`MT6873`	affected	generic	—
`MT6875`	affected	generic	—
`MT6877`	affected	generic	—
`MT6878`	affected	generic	—
`MT6879`	affected	generic	—
`MT6880`	affected	generic	—
`MT6881`	affected	generic	—
`MT6883`	affected	generic	—
`MT6885`	affected	generic	—
`MT6886`	affected	generic	—
`MT6889`	affected	generic	—
`MT6890`	affected	generic	—
`MT6891`	affected	generic	—
`MT6893`	affected	generic	—
`MT6895`	affected	generic	—
`MT6896`	affected	generic	—
`MT6897`	affected	generic	—
`MT6899`	affected	generic	—
`MT6980`	affected	generic	—
`MT6982`	affected	generic	—
`MT6983`	affected	generic	—
`MT6985`	affected	generic	—
`MT6986`	affected	generic	—
`MT6986D`	affected	generic	—
`MT6988`	affected	generic	—
`MT6989`	affected	generic	—
`MT6990`	affected	generic	—
`MT6991`	affected	generic	—
`MT6993`	affected	generic	—
`MT8666`	affected	generic	—
`MT8667`	affected	generic	—
`MT8668`	affected	generic	—
`MT8673`	affected	generic	—
`MT8675`	affected	generic	—
`MT8676`	affected	generic	—
`MT8678`	affected	generic	—
`MT8755`	affected	generic	—
`MT8765`	affected	generic	—
`MT8766`	affected	generic	—
`MT8766R`	affected	generic	—
`MT8768`	affected	generic	—
`MT8771`	affected	generic	—
`MT8775`	affected	generic	—
`MT8781`	affected	generic	—
`MT8786`	affected	generic	—
`MT8788`	affected	generic	—
`MT8788E`	affected	generic	—
`MT8789`	affected	generic	—
`MT8791`	affected	generic	—
`MT8791T`	affected	generic	—
`MT8792`	affected	generic	—
`MT8793`	affected	generic	—
`MT8795T`	affected	generic	—
`MT8796`	affected	generic	—
`MT8797`	affected	generic	—
`MT8798`	affected	generic	—
`MT8863`	affected	generic	—
`MT8873`	affected	generic	—
`MT8883`	affected	generic	—
`MT8893`	affected	generic	—

Remediation

No solution or workaround provided in the CVE record

Tracking

Advisories

No advisories available

Metrics

No CVSS v4.0

Attack Vector Adjacent Network

Attack Complexity High

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploit prediction score: < 1% (0.264% probability within 30 days)

Exploitation none

Automatable no

Technical Impact partial

References

Link	Providers
https://corp.mediatek.com/product-security-bulletin/July-2026

History

Aug 2, 2026 12:15 AM Title updated View changes

Type	Values Removed	Values Added
Title		Modem Firmware Improper Input Validation Enables Remote Denial of Service

Jul 28, 2026 4:15 PM Title updated View changes

Type	Values Removed	Values Added
Title	Improper Input Validation in MediaTek Modem Enables Remote Denial of Service

Jul 24, 2026 6:30 PM Title updated View changes

Type	Values Removed	Values Added
Title		Improper Input Validation in MediaTek Modem Enables Remote Denial of Service

Jul 22, 2026 3:00 PM Title updated View changes

Type	Values Removed	Values Added
Title	Remote Denial of Service via Improper Input Validation in MediaTek Modem

Jul 15, 2026 11:15 PM Title updated View changes

Type	Values Removed	Values Added
Title		Remote Denial of Service via Improper Input Validation in MediaTek Modem

Jul 14, 2026 11:30 AM Title updated View changes

Type	Values Removed	Values Added
Title	Remote Denial of Service via Improper Modem Input Validation

Jul 12, 2026 9:00 PM Title updated View changes

Type	Values Removed	Values Added
Title		Remote Denial of Service via Improper Modem Input Validation

Jul 11, 2026 5:00 PM Title updated View changes

Type	Values Removed	Values Added
Title	Modem Firmware Denial of Service via Improper Input Validation

Jul 10, 2026 5:30 PM Title updated View changes

Type	Values Removed	Values Added
Title		Modem Firmware Denial of Service via Improper Input Validation

Jul 9, 2026 2:45 PM Title updated View changes

Type	Values Removed	Values Added
Title	Modem Firmware Crash via Improper Input Validation Leading to Remote DoS

Jul 8, 2026 7:15 PM Title updated View changes

Type	Values Removed	Values Added
Title		Modem Firmware Crash via Improper Input Validation Leading to Remote DoS

Jul 8, 2026 3:00 AM Title updated View changes

Type	Values Removed	Values Added
Title	Covert Modem Firmware Crash Causing Remote Denial of Service

Jul 7, 2026 9:45 AM Title updated View changes

Type	Values Removed	Values Added
Title		Covert Modem Firmware Crash Causing Remote Denial of Service

Jul 6, 2026 8:30 PM Title updated View changes

Type	Values Removed	Values Added
Title	Modem Crash from Improper Input Validation Leading to Remote Denial of Service

Jul 6, 2026 3:15 AM Title updated View changes

Type	Values Removed	Values Added
Title		Modem Crash from Improper Input Validation Leading to Remote Denial of Service

Jul 5, 2026 7:15 PM Title updated View changes

Type	Values Removed	Values Added
Title	Modem input validation flaw can crash device, enabling remote denial of service

Jul 5, 2026 6:30 AM Title updated View changes

Type	Values Removed	Values Added
Title		Modem input validation flaw can crash device, enabling remote denial of service

Jul 4, 2026 10:45 PM Title updated View changes

Type	Values Removed	Values Added
Title	Modem Input Validation Crash Causing Remote Denial of Service on MediaTek Chipsets

Jul 4, 2026 11:30 AM Title updated View changes

Type	Values Removed	Values Added
Title		Modem Input Validation Crash Causing Remote Denial of Service on MediaTek Chipsets

Jul 4, 2026 3:45 AM Title updated View changes

Type	Values Removed	Values Added
Title	Remote Denial of Service via Improper Input Validation in MediaTek Modem

Jul 3, 2026 7:30 PM Title updated View changes

Type	Values Removed	Values Added
Title		Remote Denial of Service via Improper Input Validation in MediaTek Modem

Jul 3, 2026 2:00 AM Title updated View changes

Type	Values Removed	Values Added
Title	Modem Component Input Validation Failure Leads to Remote Denial of Service on MediaTek Chipsets

Jul 2, 2026 2:00 PM Title updated View changes

Type	Values Removed	Values Added
Title		Modem Component Input Validation Failure Leads to Remote Denial of Service on MediaTek Chipsets

Jul 2, 2026 4:15 AM Title updated View changes

Type	Values Removed	Values Added
Title	Modem Input Validation Crash Allowing Remote Denial of Service on MediaTek Chipsets

Jul 1, 2026 10:00 PM Title updated View changes

Type	Values Removed	Values Added
Title		Modem Input Validation Crash Allowing Remote Denial of Service on MediaTek Chipsets

Jul 1, 2026 2:30 PM First appearance in the feed. Affected vendors updated View changes

Type	Values Removed	Values Added
First Time appeared		Mediatek, Inc. Mediatek, Inc. mediatek Chipset
Vendors & Products		Mediatek, Inc. Mediatek, Inc. mediatek Chipset

Jul 1, 2026 11:30 AM Scoring metrics updated View changes

Type	Values Removed	Values Added
Metrics		cvssV3_1 `{'score': 5.3, 'vector': 'CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H'}` ssvc `{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}`

Jul 1, 2026 11:15 AM Title updated View changes

Type	Values Removed	Values Added
Title	Modem Denial of Service via Improper Input Validation on MediaTek Chipset

Jul 1, 2026 6:45 AM Title updated View changes

Type	Values Removed	Values Added
Title		Modem Denial of Service via Improper Input Validation on MediaTek Chipset

Jul 1, 2026 3:30 AM Description updated. Weaknesses updated. Added references View changes

Type	Values Removed	Values Added
Description		In Modem, there is a possible system crash due to improper input validation. 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: MOLY01816800; Issue ID: MSV-6842.
Weaknesses		CWE-288
References		https://corp.mediatek.com/product-security-bulletin/July-2026