# CVE-2026-20565: MediaTek Modem out-of-bounds write in bounds check

Source: https://junglewise.ai/threats/cve-2026-20565-in-modem-there-is-a-possible-out-of-bounds-write-due-to-an  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-02. Updated: 2026-11-02  
License: CC BY 4.0 with a link back

CVE-2026-20565 · Severity: info · Published 2026-11-02

A modem firmware component used in smartphones and IoT devices contains a flaw that allows an attacker with local access to write data beyond allocated memory boundaries. This can lead to privilege escalation, potentially giving an attacker control over the modem and the device itself without requiring special permissions or user interaction.

Technologies: [MediaTek Modem](https://junglewise.ai/threats/technologies/modem). Vendors: [MediaTek](https://junglewise.ai/threats/vendors/mediatek).

## Quick answers

**Is CVE-2026-20565 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-20565 being exploited in the wild.

**How severe is CVE-2026-20565?** Informational severity, published 2 November 2026.

**Which products and versions are affected?** MediaTek Modem.

**Is there a fix for CVE-2026-20565?** 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-2026-20565 attacked?** It is attacked with local access, in device firmware.

**Am I affected by CVE-2026-20565?** 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 vulnerability exists in MediaTek Modem firmware due to insufficient bounds validation. The vulnerability is exploitable through a local attack vector with no additional execution privileges required and requires no user interaction, enabling local privilege escalation.

## Affected products

- MediaTek Modem

## Timeline

- 2026-11-02: disclosed

## References

- [https://www.mediatek.com/product-security-bulletin/November-2026](https://www.mediatek.com/product-security-bulletin/November-2026)

## Related threats

- [MediaTek Modem privilege escalation via permissions bypass](https://junglewise.ai/threats/cve-2026-68591-in-modem-there-is-a-possible-escalation-of-privilege-due-to-a)
- [MediaTek Modem out-of-bounds write privilege escalation](https://junglewise.ai/threats/cve-2026-68589-in-modem-there-is-a-possible-out-of-bounds-write-due-to-a-missing)
- [MediaTek Modem integer overflow denial of service](https://junglewise.ai/threats/cve-2026-68588-in-modem-there-is-a-possible-way-for-xxx-to-xxxxx-due-to-an)
- [MediaTek Modem logic error denial of service](https://junglewise.ai/threats/cve-2026-20600-in-modem-there-is-a-possible-application-crash-due-to-a-logic)
- [MediaTek Modem privilege escalation due to missing permission check](https://junglewise.ai/threats/cve-2026-20599-in-modem-there-is-a-possible-escalation-of-privilege-due-to-a)