Quick answers
- Is CVE-2026-20477 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-20477 being exploited in the wild.
- How severe is CVE-2026-20477?
- Medium severity, with a CVSS score of 6, published 3 August 2026.
- Which products and versions are affected?
- MediaTek Dimensity 5G.
- Is there a fix for CVE-2026-20477?
- 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-2026-20477 attacked?
- It is attacked with local access.
- Am I affected by CVE-2026-20477?
- Check whether you run MediaTek Dimensity 5G, MediaTek Mt6991, MediaTek Mt6991 Firmware or one of the others listed. 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 out-of-bounds write (CWE-787) in the display subsystem caused by missing bounds validation. The flaw requires an attacker to already hold System privilege, meaning this is a local privilege escalation or privilege-boundary bypass vulnerability. No user interaction is required for exploitation once System access is obtained. An attacker can corrupt kernel memory or other privileged processes, potentially achieving kernel-level code execution. A patch is available; MediaTek identified this as Issue MSV-7658 with Patch ID ALPS11009963.
Affected products
- MediaTek Dimensity 5G
Timeline
- 2026-08-03: disclosed
- 2026-08-03: advisory: MediaTek Product Security Bulletin August 2026