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Software Development KitApplication · Mediatek

CVE-2026-20430

HIGH · 8.8 CVSS v3.1 Published 2026-03-02
Fix available
A fix is available. Upgrade to after 7.6.7.3 or later.
See remediation →
93/100
Remediation priority · Urgent
No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
In wlan AP FW, there is a possible out of bounds write due to an incorrect bounds check. This could lead to remote (proximal/adjacent) escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation. Patch ID: WCNCR00467553; Issue ID: MSV-5151.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

This is a firmware vulnerability in WLAN Access Point (AP) devices where an incorrect bounds check leads to an out-of-bounds write condition. The flaw allows a proximal/adjacent attacker (within Wi-Fi range) to achieve privilege escalation without requiring any user interaction or additional execution privileges.

MitigationApply the vendor patch (WCNCR00467553) to affected WLAN AP firmware. Since exploitation is possible from adjacent network proximity, prioritize updating APs in high-security environments and ensure proper network segmentation to limit attacker proximity.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Software Development KitApplication
Affected:<= 7.6.7.3
OpenwrtOperating system
Affected:= 19.07.0= 21.02.0= 23.05.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Adjacent
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Confirm device is a WLAN Access Point
    Identify if the target device is a Wi-Fi Access Point, wireless router, or AP controller. Check device documentation, web UI, or system information for device type classification.
    Affected if Device is not a WLAN AP - the vulnerability does not apply to non-Wi-Fi devices.
  2. Identify the firmware base system
    Determine if the AP runs on Mediatek SDK or OpenWrt. Check the vendor documentation, firmware build information, or system logs for 'Mediatek', 'MTK', 'OpenWrt', or specific version strings.
    Affected if Firmware is neither Mediatek SDK nor OpenWrt - different base systems have different vulnerability status.
  3. Check installed Mediatek SDK version
    For Mediatek-based APs, retrieve the SDK version from firmware release notes, system info page, or via command such as 'cat /proc/version' or 'logread' if accessible. Compare against <= 7.6.7.3.
    Affected if Mediatek SDK version is 7.6.7.3 or lower - falls within affected range.
  4. Check installed OpenWrt version
    For OpenWrt-based APs, retrieve the version via 'cat /etc/os-release' or 'opkg list-installed'. Compare against exactly 19.07.0, 21.02.0, or 23.05.0.
    Affected if OpenWrt version matches 19.07.0, 21.02.0, or 23.05.0 exactly.
  5. Verify WLAN radio is enabled
    Confirm the wireless interface is active. Check via 'iwconfig', 'wifi status', or through the AP management web UI wireless settings. The vulnerability requires WLAN functionality to be present.
    Affected if Wi-Fi radio is disabled and the AP operates in wired-only mode - attack surface is not present.

Device is affected if it is a WLAN AP running Mediatek SDK version 7.6.7.3 or lower, or OpenWrt version 19.07.0, 21.02.0, or 23.05.0, with the Wi-Fi radio enabled.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to a release after 7.6.7.3
Interim mitigation

Apply the vendor patch (WCNCR00467553) to affected WLAN AP firmware. Since exploitation is possible from adjacent network proximity, prioritize updating APs in high-security environments and ensure proper network segmentation to limit attacker proximity.

Recommended fix Moderate confidence

MediaTek SDK > 7.6.7.3 (or OpenWrt version after 23.05.0 with patched MediaTek firmware)

  1. 1. Identify the MediaTek WiFi device or OpenWrt firmware that uses the affected MediaTek SDK (<=7.6.7.3)
  2. 2. Check with MediaTek for the specific firmware version containing the WCNCR00467553 patch
  3. 3. For OpenWrt devices: Update to a newer OpenWrt release after 23.05.0 that incorporates the patched MediaTek firmware
  4. 4. For SDK users: Upgrade to MediaTek SDK version higher than 7.6.7.3 that includes the WCNCR00467553 fix
  5. 5. After updating firmware, verify the WiFi AP functionality and ensure the out-of-bounds write vulnerability is resolved
Caveat Firmware updates may require device reboot and could have compatibility implications with specific hardware configurations

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Software Development Kit Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA2.0 h
18.0 hours of engineering $3,200
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-20430 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data