CVE-2026-20430

Unauthenticated adjacent privilege escalation via incorrect bounds check

Published Mar 2, 2026 · Updated Mar 2, 2026

Out-of-bounds write in MediaTek WLAN AP Firmware SDK 7.6.7.3 and earlier allows remote attackers to escalate privileges from adjacent networks. The WLAN subcomponent applies an incorrect bounds check before a memory write; MediaTek has not disclosed the affected routine or input field. Exploitation requires adjacent-network reach but no authentication, prior execution privileges, or user interaction; success grants elevated firmware privileges.

CVSS severity8.8
High
EPSS probability0.22%
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 WLAN AP Firmware SDK 7.6.7.3 and earlier allows remote attackers to escalate privileges from adjacent networks. The WLAN subcomponent applies an incorrect bounds check before a memory write; MediaTek has not disclosed the affected routine or input field. Exploitation requires adjacent-network reach but no authentication, prior execution privileges, or user interaction; success grants elevated firmware privileges.

The record

CVE
CVE-2026-20430
Published
Mar 2, 2026
Updated
Mar 2, 2026
Vendor
MediaTek
Product
MediaTek WLAN AP Firmware
Classifications
CWE-787
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 2, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 2, 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=SDK release 7.6.7.3 and before / openWRT 19.07, 21.02, 23.05

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

MediaTek · MediaTek WLAN AP Firmwareversion=SDK release 7.6.7.3 and before / openWRT 19.07, 21.02, 23.05

Published CVSS scores

8.8CISA-ADPCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write

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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