# CVE-2026-20521: MediaTek Video HAL privilege escalation in missing bounds check

Source: https://junglewise.ai/threats/cve-2026-20521-in-video-hal-there-is-a-possible-escalation-of-privilege-due-to-a  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-05. Updated: 2026-10-05  
License: CC BY 4.0 with a link back

CVE-2026-20521 · Severity: high · CVSS 8.4 · Published 2026-10-05

MediaTek's Video Hardware Abstraction Layer (HAL) contains a memory bounds checking flaw that allows a local attacker to escalate privileges without needing special permissions or user interaction. This affects smartphones, tablets, and other devices using affected MediaTek chipsets, potentially giving attackers full device control.

Vendors: [MediaTek](https://junglewise.ai/threats/vendors/mediatek).

## Quick answers

**Is CVE-2026-20521 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-20521 being exploited in the wild.

**How severe is CVE-2026-20521?** High severity, with a CVSS score of 8.4, published 5 October 2026.

**Which products and versions are affected?** MediaTek Dimensity chipset MT6813, MT6815, MT6833, MT6835, MT6853, MT6855, MT6858, MT6873, MT6875, MT6877, MT6878, MT6879, MT6880, MT6881, MT6883, MT6885, MT6886, MT6889, MT6890, MT6891, MT6893, MT6895, MT6896; MediaTek Helio chipset MT2716, MT2735, MT2737.

**Is there a fix for CVE-2026-20521?** 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-2026-20521 attacked?** It is attacked with local access, in device firmware.

**Am I affected by CVE-2026-20521?** Check whether you run MediaTek Dimensity chipset or MediaTek Helio chipset 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 missing bounds check in the Video HAL component that permits local privilege escalation. An unprivileged local process can trigger the flaw with no user interaction required, likely through memory corruption or an out-of-bounds write to elevate execution privileges.

## Affected products

- MediaTek Dimensity chipset MT6813, MT6815, MT6833, MT6835, MT6853, MT6855, MT6858, MT6873, MT6875, MT6877, MT6878, MT6879, MT6880, MT6881, MT6883, MT6885, MT6886, MT6889, MT6890, MT6891, MT6893, MT6895, MT6896
- MediaTek Helio chipset MT2716, MT2735, MT2737

## Timeline

- 2026-10-05: disclosed

## References

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