# CVE-2026-20466: MediaTek secure boot heap buffer overflow privilege escalation

Source: https://junglewise.ai/threats/cve-2026-20466-mediatek-secure-boot-heap-buffer-overflow-privilege-escalation  
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-2026-20466 · Severity: medium · CVSS 6.1 · Published 2026-08-03

MediaTek's secure boot component, which protects the boot process on mobile devices and IoT products, contains a heap buffer overflow vulnerability. An attacker with physical access to a device can exploit this flaw to escalate privileges and gain unauthorized control over the system, potentially allowing them to modify firmware or compromise the entire device.

Technologies: [MediaTek MT2737](https://junglewise.ai/threats/technologies/mt2737), [MediaTek Mt6880](https://junglewise.ai/threats/technologies/mt6880), [MediaTek Mt6890](https://junglewise.ai/threats/technologies/mt6890), [MediaTek MT6990](https://junglewise.ai/threats/technologies/mt6990). Vendors: [MediaTek](https://junglewise.ai/threats/vendors/mediatek).

## Quick answers

**Is CVE-2026-20466 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-20466 being exploited in the wild.

**How severe is CVE-2026-20466?** Medium severity, with a CVSS score of 6.1, published 3 August 2026.

**Which products and versions are affected?** MediaTek MT2737 Unspecified (Patch ID: AUTO00845351); MediaTek Mt6880 Unspecified (Patch ID: ALPS11072643); MediaTek Mt6890 Unspecified (Patch ID: ALPS11072643); MediaTek MT6990 Unspecified (Patch ID: ALPS11072643).

**Is there a fix for CVE-2026-20466?** A patch was published: Patches available: AUTO00845351 (MT2737), ALPS11072643 (MT6880/MT6890/MT6990) Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-20466 attacked?** It is attacked with physical access, in device firmware.

**Am I affected by CVE-2026-20466?** Check whether you run MediaTek MT2737, MediaTek Mt6880, MediaTek Mt6890 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

The vulnerability is a heap buffer overflow in MediaTek's secure boot implementation (vulnerable component: sec boot). The attack vector is physical access to the device; no additional execution privileges or user interaction is required. An attacker can trigger the buffer overflow to overwrite heap memory, leading to local privilege escalation. Patches are available under Patch IDs AUTO00845351 (for MT2737) and ALPS11072643 (for MT6880, MT6890, MT6990). The vendor was notified at least two months prior to public disclosure, and no active exploitation in the wild has been reported as of the advisory date.

## Affected products

- MediaTek MT2737 Unspecified (Patch ID: AUTO00845351)
- MediaTek MT6880 Unspecified (Patch ID: ALPS11072643)
- MediaTek MT6890 Unspecified (Patch ID: ALPS11072643)
- MediaTek MT6990 Unspecified (Patch ID: ALPS11072643)

## Timeline

- 2026-08-03: disclosed: MediaTek Product Security Bulletin published; CVE-2026-20466 assigned
- 2026-06-03: other: Device OEMs notified at least two months prior to disclosure
- patched: Patches available: AUTO00845351 (MT2737), ALPS11072643 (MT6880/MT6890/MT6990)

## References

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

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