CVE-2026-20446

Physical denial of service via secure-boot integer overflow

Published Apr 7, 2026 · Updated Apr 7, 2026

Out-of-bounds write in MediaTek Chipset MT6813 secure boot allows physically proximate attackers with user privileges to interrupt service. The secure-boot component performs an undisclosed integer calculation that can overflow and use the resulting value to write outside the intended memory bounds. Physical access and user execution privileges are required; no user interaction is needed, and the documented consequence is availability loss without reported data exposure or modification.

CVSS severity4.3
Medium
EPSS probability0.19%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds write in MediaTek Chipset MT6813 secure boot allows physically proximate attackers with user privileges to interrupt service. The secure-boot component performs an undisclosed integer calculation that can overflow and use the resulting value to write outside the intended memory bounds. Physical access and user execution privileges are required; no user interaction is needed, and the documented consequence is availability loss without reported data exposure or modification.

The record

CVE
CVE-2026-20446
Published
Apr 7, 2026
Updated
Apr 7, 2026
Vendor
MediaTek
Product
MediaTek Chipset
Classifications
CWE-190, CWE-787, T1499.004
Attack vector
physical
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 7, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 7, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=MT6813

What conditions does exploitation require?

Attack vectorphysical
Required privilegesauthenticated

What is affected?

MediaTek · MediaTek Chipsetversion=MT6813

Published CVSS scores

4.3NVDCVSS:3.1/AV:P/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
4.3CISA-ADPCVSS:3.1/AV:P/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorphysical
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-190Integer Overflow or Wraparound
CWE-787Out-of-bounds Write
T1499.004Application or System Exploitation

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

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Your stack

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