7.5
HIGH CVSS 3.1
CVE-2026-20479
Modem Out-of-Bounds Read Vulnerability
Description

In Modem, there is a possible out of bounds read 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: MOLY00741071; Issue ID: MSV-7620.

INFO

Published Date :

Aug. 3, 2026, 3:16 a.m.

Last Modified :

Aug. 19, 2026, 5:17 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-20479 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Mediatek mt2735
2 Mediatek mt6833
3 Mediatek mt6853
4 Mediatek mt6855
5 Mediatek mt6873
6 Mediatek mt6875
7 Mediatek mt6877
8 Mediatek mt6880
9 Mediatek mt6883
10 Mediatek mt6885
11 Mediatek mt6889
12 Mediatek mt6890
13 Mediatek mt6891
14 Mediatek mt6893
15 Mediatek mt8675
16 Mediatek mt8791
17 Mediatek mt8791t
18 Mediatek mt8797
19 Mediatek mt8771
20 Mediatek mt2735_firmware
21 Mediatek mt6833_firmware
22 Mediatek mt6853_firmware
23 Mediatek mt6855_firmware
24 Mediatek mt6873_firmware
25 Mediatek mt6875_firmware
26 Mediatek mt6877_firmware
27 Mediatek mt6880_firmware
28 Mediatek mt6883_firmware
29 Mediatek mt6885_firmware
30 Mediatek mt6889_firmware
31 Mediatek mt6890_firmware
32 Mediatek mt6891_firmware
33 Mediatek mt6893_firmware
34 Mediatek mt8675_firmware
35 Mediatek mt8771_firmware
36 Mediatek mt8791t_firmware
37 Mediatek mt8797_firmware
38 Mediatek mt8791_firmware
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 134c704f-9b21-4f2e-91b3-4a467353bcc0
CVSS 3.1 HIGH 134c704f-9b21-4f2e-91b3-4a467353bcc0
Solution
Apply the vendor-supplied patch to fix the out-of-bounds read vulnerability.
  • Apply the vendor patch to address the vulnerability.
  • Update the modem firmware to the latest version.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-20479.

URL Resource
https://www.mediatek.com/product-security-bulletin/August-2026 Vendor Advisory
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-20479 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-20479 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-20479 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-20479 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • Initial Analysis by [email protected]

    Aug. 19, 2026

    Action Type Old Value New Value
    Added CPE Configuration AND OR *cpe:2.3:o:mediatek:mt2735_firmware:-:*:*:*:*:*:*:* OR cpe:2.3:h:mediatek:mt2735:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:mediatek:mt6833_firmware:-:*:*:*:*:*:*:* OR cpe:2.3:h:mediatek:mt6833:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:mediatek:mt6853_firmware:-:*:*:*:*:*:*:* OR cpe:2.3:h:mediatek:mt6853:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:mediatek:mt6855_firmware:-:*:*:*:*:*:*:* OR cpe:2.3:h:mediatek:mt6855:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:mediatek:mt6873_firmware:-:*:*:*:*:*:*:* OR cpe:2.3:h:mediatek:mt6873:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:mediatek:mt6875_firmware:-:*:*:*:*:*:*:* OR cpe:2.3:h:mediatek:mt6875:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:mediatek:mt6877_firmware:-:*:*:*:*:*:*:* OR cpe:2.3:h:mediatek:mt6877:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:mediatek:mt6880_firmware:-:*:*:*:*:*:*:* OR cpe:2.3:h:mediatek:mt6880:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:mediatek:mt6883_firmware:-:*:*:*:*:*:*:* OR cpe:2.3:h:mediatek:mt6883:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:mediatek:mt6885_firmware:-:*:*:*:*:*:*:* OR cpe:2.3:h:mediatek:mt6885:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:mediatek:mt6889_firmware:-:*:*:*:*:*:*:* OR cpe:2.3:h:mediatek:mt6889:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:mediatek:mt6890_firmware:-:*:*:*:*:*:*:* OR cpe:2.3:h:mediatek:mt6890:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:mediatek:mt6891_firmware:-:*:*:*:*:*:*:* OR cpe:2.3:h:mediatek:mt6891:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:mediatek:mt6893_firmware:-:*:*:*:*:*:*:* OR cpe:2.3:h:mediatek:mt6893:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:mediatek:mt8675_firmware:-:*:*:*:*:*:*:* OR cpe:2.3:h:mediatek:mt8675:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:mediatek:mt8771_firmware:-:*:*:*:*:*:*:* OR cpe:2.3:h:mediatek:mt8771:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:mediatek:mt8791_firmware:-:*:*:*:*:*:*:* OR cpe:2.3:h:mediatek:mt8791:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:mediatek:mt8791t_firmware:-:*:*:*:*:*:*:* OR cpe:2.3:h:mediatek:mt8791t:-:*:*:*:*:*:*:*
    Added CPE Configuration AND OR *cpe:2.3:o:mediatek:mt8797_firmware:-:*:*:*:*:*:*:* OR cpe:2.3:h:mediatek:mt8797:-:*:*:*:*:*:*:*
    Added Reference Type MediaTek, Inc.: https://www.mediatek.com/product-security-bulletin/August-2026 Types: Vendor Advisory
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Aug. 03, 2026

    Action Type Old Value New Value
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
    Added SSVC {'id': 'CVE-2026-20479', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-08-03T18:58:43.400693Z'}
  • New CVE Received by [email protected]

    Aug. 03, 2026

    Action Type Old Value New Value
    Added Affected [{'vendor': 'MediaTek, Inc.', 'product': 'MediaTek chipset', 'versions': [{'status': 'affected', 'version': 'MT2735'}, {'status': 'affected', 'version': 'MT6833'}, {'status': 'affected', 'version': 'MT6853'}, {'status': 'affected', 'version': 'MT6855'}, {'status': 'affected', 'version': 'MT6873'}, {'status': 'affected', 'version': 'MT6875'}, {'status': 'affected', 'version': 'MT6877'}, {'status': 'affected', 'version': 'MT6880'}, {'status': 'affected', 'version': 'MT6883'}, {'status': 'affected', 'version': 'MT6885'}, {'status': 'affected', 'version': 'MT6889'}, {'status': 'affected', 'version': 'MT6890'}, {'status': 'affected', 'version': 'MT6891'}, {'status': 'affected', 'version': 'MT6893'}, {'status': 'affected', 'version': 'MT8675'}, {'status': 'affected', 'version': 'MT8771'}, {'status': 'affected', 'version': 'MT8791'}, {'status': 'affected', 'version': 'MT8791T'}, {'status': 'affected', 'version': 'MT8797'}], 'defaultStatus': 'unaffected'}]
    Added Description In Modem, there is a possible out of bounds read 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: MOLY00741071; Issue ID: MSV-7620.
    Added CWE CWE-125
    Added Reference https://www.mediatek.com/product-security-bulletin/August-2026
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.