Local service interruption via unchecked Wi-Fi write
Published Aug 3, 2026 · Updated Aug 3, 2026
Out-of-bounds write in MediaTek chipset Wi-Fi on MT6890, MT6988, and MT6990 allows local users to interrupt service. The Wi-Fi subcomponent omits a bounds check before a write, allowing the operation to extend beyond the intended buffer. Exploitation requires existing System privilege, needs no user interaction, and can cause a local service interruption; no data exposure or modification is reported.
Summary
What happened
Out-of-bounds write in MediaTek chipset Wi-Fi on MT6890, MT6988, and MT6990 allows local users to interrupt service. The Wi-Fi subcomponent omits a bounds check before a write, allowing the operation to extend beyond the intended buffer. Exploitation requires existing System privilege, needs no user interaction, and can cause a local service interruption; no data exposure or modification is reported.
The record
- CVE
- CVE-2026-20493
- Published
- Aug 3, 2026
- Updated
- Aug 3, 2026
- Vendor
- MediaTek
- Product
- MediaTek Chipset
- Classifications
- CWE-787, T1499
- Attack vector
- local
- Privileges
- admin
Timeline
How it unfolded
- Aug 3, 2026CVE publishedPublication date reported by the CVE source.
- Aug 3, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=MT6890
- Affected versionversion=MT6988
- Affected versionversion=MT6990
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo