CVE-2026-20457: MediaTek Modem improper input validation in multiple chipsets

CVE-2026-20457 · Severity: info · Published 2026-07-01

A vulnerability in the modem component of various MediaTek chipsets could allow a nearby attacker to crash a mobile device. By using a rogue base station to mimic a legitimate cellular tower, an attacker can trigger a system failure on any device that connects to it. This results in a total loss of cellular connectivity and device stability for the user until the system is recovered.

Technologies: MediaTek MT2735, MediaTek MT2737, MediaTek Mt6739, MediaTek Mt6761, MediaTek Mt6765, MediaTek Mt6768, MediaTek MT6769, MediaTek MT6779, MediaTek Mt6781, MediaTek MT6785, MediaTek Mt6789, MediaTek MT6833, MediaTek Mt6853, MediaTek MT6873, MediaTek Mt6877, MediaTek Mt6885, MediaTek Mt6889, MediaTek MT6891, MediaTek Mt6893, MediaTek Mt6895, MediaTek Mt6983, MediaTek Mt6985, MediaTek Mt8766, MediaTek Mt8768, MediaTek Mt8781. Vendors: MediaTek.

Quick answers

Is CVE-2026-20457 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-20457 being exploited in the wild.
How severe is CVE-2026-20457?
Informational severity, published 1 July 2026.
Which products and versions are affected?
MediaTek, Inc. MediaTek chipset MT2735, MT2737, MT6739, MT6761, MT6762, MT6763, MT6765, MT6767, MT6768, MT6769, MT6771, MT6779, MT6781, MT6783, MT6785, MT6789, MT6833, MT6853, MT6855, MT6873, MT6875, MT6877, MT6879, MT6880, MT6883, MT6885, MT6886, MT6889, MT6890, MT6891, MT6893, MT6895, MT6896, MT6980, MT6983, MT6985, MT6989, MT6990, MT8666, MT8667, MT8673, MT8675, MT8765, MT8766, MT8766R, MT8768, MT8771, MT8781.
Is there a fix for CVE-2026-20457?
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-2026-20457 attacked?
It is attacked from the adjacent network, in device firmware.
Am I affected by CVE-2026-20457?
Check whether you run MediaTek MT2735, MediaTek MT2737, MediaTek Mt6739 or one of the others listed. 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, specifically identified as a NULL pointer dereference (CWE-476). The flaw is triggered when a User Equipment (UE) device connects to a rogue base station controlled by an attacker. The attacker can send malformed inputs that the modem fails to validate, resulting in a system crash and subsequent denial of service. No special execution privileges or user interaction are required for exploitation. MediaTek has released a patch under ID MOLY01826924 to address this issue.

Affected products

  • MediaTek, Inc. MediaTek chipset MT2735, MT2737, MT6739, MT6761, MT6762, MT6763, MT6765, MT6767, MT6768, MT6769, MT6771, MT6779, MT6781, MT6783, MT6785, MT6789, MT6833, MT6853, MT6855, MT6873, MT6875, MT6877, MT6879, MT6880, MT6883, MT6885, MT6886, MT6889, MT6890, MT6891, MT6893, MT6895, MT6896, MT6980, MT6983, MT6985, MT6989, MT6990, MT8666, MT8667, MT8673, MT8675, MT8765, MT8766, MT8766R, MT8768, MT8771, MT8781

Timeline

  • 2026-07-01: advisory: MediaTek published the July 2026 Product Security Bulletin.
  • 2026-07-01: disclosed: CVE record published to the NVD.

References

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