# CVE-2026-20494: MediaTek WiFi out-of-bounds read

Source: https://junglewise.ai/threats/cve-2026-20494-mediatek-wifi-out-of-bounds-read  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-03. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-20494 · Severity: medium · CVSS 5.5 · Published 2026-08-03

MediaTek's WiFi driver contains a missing bounds check that allows local information disclosure. An attacker with System-level privileges can read memory outside allocated buffers, potentially exposing sensitive data. No user interaction is required for exploitation.

Technologies: [MediaTek Mt6890](https://junglewise.ai/threats/technologies/mt6890), [MediaTek Mt6890 Firmware](https://junglewise.ai/threats/technologies/mt6890-firmware), [MediaTek MT6988](https://junglewise.ai/threats/technologies/mt6988), [MediaTek Mt6988 Firmware](https://junglewise.ai/threats/technologies/mt6988-firmware), [MediaTek MT6990](https://junglewise.ai/threats/technologies/mt6990), [MediaTek Mt6990 Firmware](https://junglewise.ai/threats/technologies/mt6990-firmware). Vendors: [MediaTek](https://junglewise.ai/threats/vendors/mediatek).

## Quick answers

**Is CVE-2026-20494 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-20494 being exploited in the wild.

**How severe is CVE-2026-20494?** Medium severity, with a CVSS score of 5.5, published 3 August 2026.

**Which products and versions are affected?** MediaTek WiFi driver <UNKNOWN>.

**Is there a fix for CVE-2026-20494?** 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-2026-20494 attacked?** It is attacked with local access.

**Am I affected by CVE-2026-20494?** Check whether you run MediaTek Mt6890, MediaTek Mt6890 Firmware, MediaTek MT6988 or one of the others listed 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

This vulnerability is a missing bounds check in the MediaTek WiFi subsystem that leads to an out-of-bounds read. The root cause stems from insufficient validation when processing WiFi-related operations, allowing an attacker to read memory beyond the intended buffer boundaries. Exploitation requires System privilege level access and no user interaction. An attacker can disclose sensitive information stored in adjacent memory regions. MediaTek has issued patches identified by Patch IDs ALPS10960006, BORA00155314, BORA00155001, and BORA00154907.

## Affected products

- MediaTek WiFi driver <UNKNOWN>

## Timeline

- 2026-08-03: disclosed

## References

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

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- [MediaTek ccci out of bounds write](https://junglewise.ai/threats/cve-2026-20552-in-ccci-there-is-a-possible-out-of-bounds-write-due-to-a-missing)
- [MediaTek vdec out-of-bounds write in type confusion](https://junglewise.ai/threats/cve-2026-20579-in-vdec-there-is-a-possible-out-of-bounds-write-due-to-type)
- [MediaTek out of bounds write in modem](https://junglewise.ai/threats/cve-2026-20544-in-meta-there-is-a-possible-out-of-bounds-write-due-to-a-missing)
- [MediaTek Modem information disclosure due to logic error](https://junglewise.ai/threats/cve-2026-20543-in-modem-there-is-a-possible-information-disclosure-due-to-a)
- [MediaTek Modem out-of-bounds read due to missing permission check](https://junglewise.ai/threats/cve-2026-20538-in-modem-there-is-a-possible-out-of-bounds-read-due-to-a-missing)