Quick answers
- Is CVE-2026-20561 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-20561 being exploited in the wild.
- How severe is CVE-2026-20561?
- Informational severity, published 2 November 2026.
- Which products and versions are affected?
- MediaTek Modem.
- Is there a fix for CVE-2026-20561?
- 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-2026-20561 attacked?
- It is attacked from the adjacent network or over the network, in device firmware.
- Am I affected by CVE-2026-20561?
- 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
The vulnerability is an out-of-bounds write in MediaTek modem firmware caused by insufficient bounds validation. An attacker operating a rogue base station can send a specially crafted signal to trigger the memory corruption when a user equipment (UE) connects to it. The impact is remote denial of service via modem crash; the attack vector is network-adjacent (requires the victim device to connect to the attacker's base station).
Affected products
- MediaTek Modem
Timeline
- 2026-11-02: disclosed