Is CVE-2026-20459 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-20459 being exploited in the wild.

How severe is CVE-2026-20459?

Informational severity, published 1 July 2026.

Which products and versions are affected?

MediaTek Chipset MT2716, MT2735, MT2737, MT6739, MT6761, MT6762, MT6763, MT6765, MT6767, MT6768, MT6769, MT6771, MT6779, MT6781, MT6783, MT6785, MT6789, MT6813, MT6833, MT6835, MT6853, MT6855, MT6858, MT6873, MT6875, MT6877, MT6878, MT6879, MT6880, MT6881, MT6883, MT6885, MT6886, MT6889, MT6890, MT6891, MT6893, MT6895, MT6896, MT6897, MT6899, MT6980, MT6982, MT6983, MT6985, MT6986, MT6986D, MT6988.

Is there a fix for CVE-2026-20459?

No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

How is CVE-2026-20459 attacked?

It is attacked from the adjacent network, in device firmware.

Am I affected by CVE-2026-20459?

Check whether you run MediaTek Chipset at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-20459: MediaTek Chipset improper input validation in Modem

CVE-2026-20459 · Severity: info · Published 2026-07-01

A vulnerability exists in the modem component of several MediaTek chipsets used in mobile devices. If a device connects to a malicious base station controlled by an attacker, it could cause the modem to crash, leading to a total loss of cellular connectivity. This is a denial-of-service attack that does not require any user interaction or special permissions on the device.

Technologies: MediaTek Chipset. Vendors: MediaTek.

Quick answers

Is CVE-2026-20459 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-20459 being exploited in the wild.
How severe is CVE-2026-20459?: Informational severity, published 1 July 2026.
Which products and versions are affected?: MediaTek Chipset MT2716, MT2735, MT2737, MT6739, MT6761, MT6762, MT6763, MT6765, MT6767, MT6768, MT6769, MT6771, MT6779, MT6781, MT6783, MT6785, MT6789, MT6813, MT6833, MT6835, MT6853, MT6855, MT6858, MT6873, MT6875, MT6877, MT6878, MT6879, MT6880, MT6881, MT6883, MT6885, MT6886, MT6889, MT6890, MT6891, MT6893, MT6895, MT6896, MT6897, MT6899, MT6980, MT6982, MT6983, MT6985, MT6986, MT6986D, MT6988.
Is there a fix for CVE-2026-20459?: No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-20459 attacked?: It is attacked from the adjacent network, in device firmware.
Am I affected by CVE-2026-20459?: Check whether you run MediaTek Chipset at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

An improper input validation vulnerability exists in the MediaTek Modem firmware. An attacker can exploit this by operating a rogue base station (eNodeB/gNodeB) that sends malformed or unexpected inputs to a connecting User Equipment (UE). Successful exploitation results in a system crash of the modem component, causing a denial of service. No additional execution privileges or user interactions are required for the attack. MediaTek has released a patch under ID MOLY01816800 to address this issue.

Affected products

MediaTek, Inc. MediaTek chipset MT2716, MT2735, MT2737, MT6739, MT6761, MT6762, MT6763, MT6765, MT6767, MT6768, MT6769, MT6771, MT6779, MT6781, MT6783, MT6785, MT6789, MT6813, MT6833, MT6835, MT6853, MT6855, MT6858, MT6873, MT6875, MT6877, MT6878, MT6879, MT6880, MT6881, MT6883, MT6885, MT6886, MT6889, MT6890, MT6891, MT6893, MT6895, MT6896, MT6897, MT6899, MT6980, MT6982, MT6983, MT6985, MT6986, MT6986D, MT6988

Timeline

2026-07-01: advisory
2026-07-01: disclosed

References

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

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