CVE-2026-20504: mt2735 — Fix

Description

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: MOLY00755024; Issue ID: MSV-7865.

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CVSS v3.1 Score

5.3

MEDIUM

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

EPSS — Exploit Prediction

0.0019

Probability of exploitation

0.09%

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-617 CWE-617

Affected Products

Vendor	Product	Versions
mediatek	mt2735_firmware	All
mediatek	mt2735	All
mediatek	mt6833_firmware	All
mediatek	mt6833	All
mediatek	mt6853_firmware	All
mediatek	mt6853	All
mediatek	mt6855_firmware	All
mediatek	mt6855	All
mediatek	mt6873_firmware	All
mediatek	mt6873	All
mediatek	mt6875_firmware	All
mediatek	mt6875	All
mediatek	mt6877_firmware	All
mediatek	mt6877	All
mediatek	mt6880_firmware	All
mediatek	mt6880	All
mediatek	mt6883_firmware	All
mediatek	mt6883	All
mediatek	mt6885_firmware	All
mediatek	mt6885	All
mediatek	mt6889_firmware	All
mediatek	mt6889	All
mediatek	mt6890_firmware	All
mediatek	mt6890	All
mediatek	mt6891_firmware	All
mediatek	mt6891	All
mediatek	mt6893_firmware	All
mediatek	mt6893	All
mediatek	mt8675_firmware	All
mediatek	mt8675	All
mediatek	mt8771_firmware	All
mediatek	mt8771	All
mediatek	mt8791_firmware	All
mediatek	mt8791	All
mediatek	mt8791t_firmware	All
mediatek	mt8791t	All
mediatek	mt8797_firmware	All
mediatek	mt8797	All

References

Advisories & Patches

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

Frequently Asked Questions

What is CVE-2026-20504? +

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: MOLY00755024; Issue ID: MSV-7865. It has a CVSS v3.1 base score of 5.3 (MEDIUM).

How severe is CVE-2026-20504? +

CVE-2026-20504 has a CVSS v3.1 score of 5.3 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0019, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-20504? +

CVE-2026-20504 affects products from mediatek, specifically: mt2735, mt2735_firmware, mt6833, mt6833_firmware, mt6853, mt6853_firmware, mt6855, mt6855_firmware, mt6873, mt6873_firmware, mt6875, mt6875_firmware, mt6877, mt6877_firmware, mt6880, mt6880_firmware, mt6883, mt6883_firmware, mt6885, mt6885_firmware, mt6889, mt6889_firmware, mt6890, mt6890_firmware, mt6891, mt6891_firmware, mt6893, mt6893_firmware, mt8675, mt8675_firmware, mt8771, mt8771_firmware, mt8791, mt8791_firmware, mt8791t, mt8791t_firmware, mt8797, mt8797_firmware. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-20504? +

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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