CVE-2026-20546: MediaTek Modem out-of-bounds write

CVE-2026-20546 · Severity: info · Published 2026-11-02

A modem firmware component in MediaTek chipsets contains an out-of-bounds write vulnerability due to improper bounds checking. An attacker controlling a rogue cellular base station can trigger this flaw to gain elevated privileges on a connected mobile device, without requiring user interaction or additional exploits.

Technologies: MediaTek Modem. Vendors: MediaTek.

Quick answers

Is CVE-2026-20546 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-20546 being exploited in the wild.
How severe is CVE-2026-20546?
Informational severity, published 2 November 2026.
Which products and versions are affected?
MediaTek Modem.
Is there a fix for CVE-2026-20546?
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-2026-20546 attacked?
It is attacked over the network, in device firmware.
Am I affected by CVE-2026-20546?
Check whether you run MediaTek Modem. 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 out-of-bounds write in the modem firmware results from incorrect bounds validation. The vulnerability is triggered when a UE connects to an attacker-controlled base station, allowing remote privilege escalation via network-level attack with no preconditions. The modem firmware processes untrusted base station data without sufficient validation.

Affected products

  • MediaTek Modem

Timeline

  • 2026-11-02: disclosed

References

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