CVE-2026-20528: mt2735 Memory Corruption — Fix

Description

In ccci, there is a possible out of bounds write and read due to a missing bounds check. This could lead to local information disclosure, memory corruption, crashes, or privilege escalation if a malicious actor has already obtained the System privilege. User interaction is needed for exploitation. Patch ID: ALPS11428950 (Note: For MT6880, MT6890) / ALPS10563453 (Note: For MT6980D, MT6990, MT6986, MT6986D, MT6813, MT6988) / AUTO00858766 (Note: For MT2735, MT2737); Issue ID: MSV-9893.

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CVSS v3.1 Score

6.7

MEDIUM

CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

EPSS — Exploit Prediction

0.0012

Probability of exploitation

0.02%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-787 Out-of-bounds Write

Affected Products

Vendor	Product	Versions
mediatek	mt2735_firmware	All
mediatek	mt2735	All
mediatek	mt2737_firmware	All
mediatek	mt2737	All
mediatek	mt6813_firmware	All
mediatek	mt6813	All
mediatek	mt6880_firmware	All
mediatek	mt6880	All
mediatek	mt6890_firmware	All
mediatek	mt6890	All
mediatek	mt6980d_firmware	All
mediatek	mt6980d	All
mediatek	mt6986_firmware	All
mediatek	mt6986	All
mediatek	mt6986d_firmware	All
mediatek	mt6986d	All
mediatek	mt6988_firmware	All
mediatek	mt6988	All
mediatek	mt6990_firmware	All
mediatek	mt6990	All

References

Advisories & Patches

https://www.mediatek.com/product-security-bulletin/October-2026

Frequently Asked Questions

What is CVE-2026-20528? +

In ccci, there is a possible out of bounds write and read due to a missing bounds check. This could lead to local information disclosure, memory corruption, crashes, or privilege escalation if a malicious actor has already obtained the System privilege. User interaction is needed for exploitation. Patch ID: ALPS11428950 (Note: For MT6880, MT6890) / ALPS10563453 (Note: For MT6980D, MT6990, MT6986, MT6986D, MT6813, MT6988) / AUTO00858766 (Note: For MT2735, MT2737); Issue ID: MSV-9893. It has a CVSS v3.1 base score of 6.7 (MEDIUM).

How severe is CVE-2026-20528? +

CVE-2026-20528 has a CVSS v3.1 score of 6.7 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0012, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-20528? +

CVE-2026-20528 affects products from mediatek, specifically: mt2735, mt2735_firmware, mt2737, mt2737_firmware, mt6813, mt6813_firmware, mt6880, mt6880_firmware, mt6890, mt6890_firmware, mt6980d, mt6980d_firmware, mt6986, mt6986_firmware, mt6986d, mt6986d_firmware, mt6988, mt6988_firmware, mt6990, mt6990_firmware. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-20528? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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