CVE-2026-20519

Analyzed Analyzed - Analysis Complete

Out-of-Bounds Write in Modem Firmware

Publication date: 2026-10-05

Last updated on: 2026-10-08

Assigner: MediaTek, Inc.

Description

In Modem, there is a possible out of bounds write due to a missing bounds check. This could lead to remote escalation of privilege, 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: MOLY01778993; Issue ID: MSV-8898.

CVSS Scores

EPSS Scores

Probability:
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Meta Information

Published

2026-10-05

Last Modified

2026-10-08

Generated

2026-10-19

AI Q&A

2026-10-05

EPSS Evaluated

2026-10-18

NVD

CVE-2026-20519

EUVD

EUVD-2026-92210

Affected Vendors & Products

Vendor	Product	Version / Range
mediatek	mt6833_firmware	*
mediatek	mt6835_firmware	*
mediatek	mt6853_firmware	*
mediatek	mt6855_firmware	*
mediatek	mt6858_firmware	*
mediatek	mt6873_firmware	*
mediatek	mt6875_firmware	*
mediatek	mt6877_firmware	*
mediatek	mt6878_firmware	*
mediatek	mt6879_firmware	*
mediatek	mt6880_firmware	*
mediatek	mt6881_firmware	*
mediatek	mt6883_firmware	*
mediatek	mt6885_firmware	*
mediatek	mt6886_firmware	*
mediatek	mt6889_firmware	*
mediatek	mt6890_firmware	*
mediatek	mt6891_firmware	*
mediatek	mt6893_firmware	*
mediatek	mt6895_firmware	*
mediatek	mt6896_firmware	*
mediatek	mt6897_firmware	*
mediatek	mt6899_firmware	*
mediatek	mt6980_firmware	*
mediatek	mt6982_firmware	*
mediatek	mt6983_firmware	*
mediatek	mt6985_firmware	*
mediatek	mt6986_firmware	*
mediatek	mt6988_firmware	*
mediatek	mt6989_firmware	*
mediatek	mt6990_firmware	*
mediatek	mt6991_firmware	*
mediatek	mt6993_firmware	*
mediatek	mt8668_firmware	*
mediatek	mt8676_firmware	*
mediatek	mt8678_firmware	*
mediatek	mt8755_firmware	*
mediatek	mt8771_firmware	*
mediatek	mt8775_firmware	*
mediatek	mt8791_firmware	*
mediatek	mt2716_firmware	*
mediatek	mt2735_firmware	*
mediatek	mt2737_firmware	*
mediatek	mt6813_firmware	*
mediatek	mt6815_firmware	*
mediatek	mt8791t_firmware	*
mediatek	mt8792_firmware	*
mediatek	mt8793_firmware	*
mediatek	mt8796_firmware	*
mediatek	mt8797_firmware	*
mediatek	mt8798_firmware	*
mediatek	mt8863_firmware	*
mediatek	mt8873_firmware	*
mediatek	mt8883_firmware	*
mediatek	mt8893_firmware	*
mediatek	mt8695_firmware	*
mediatek	mt8696_firmware	*

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-787	The product writes data past the end, or before the beginning, of the intended buffer.

Attack-Flow Graph

Executive Summary

This is an out-of-bounds write vulnerability in MediaTek's modem subcomponent caused by a missing bounds check. It could allow remote code execution or system compromise if a user device connects to a malicious base station controlled by an attacker. No user interaction or additional privileges are required for exploitation.

Detection Guidance

Detection requires checking if your device uses an affected MediaTek chipset and verifying if the latest security patches have been applied. Contact your device manufacturer for specific detection methods. MediaTek has provided patches to OEMs, so check for firmware updates from your device vendor.

Impact Analysis

If exploited, this vulnerability could allow an attacker to gain control over your device by tricking it into connecting to a rogue base station. This could lead to unauthorized access, data theft, or further malicious activities on your device without your knowledge.

Compliance Impact

This vulnerability could potentially lead to unauthorized access or control of affected devices, which may compromise sensitive user data. This could impact compliance with regulations like GDPR (data protection) or HIPAA (healthcare data) if exploited in devices handling such data. However, specific compliance impacts depend on device usage and data processed.

Mitigation Strategies

Immediately apply the latest security patches provided by your device manufacturer. If no patch is available, avoid connecting to untrusted networks or rogue base stations. Monitor MediaTek's security bulletins for updates and follow OEM guidance for affected devices.

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