What is the CVSS score of CVE-2026-20430?

CVE-2026-20430 has a CVSS 3.1 base score of 8.8 (High). CVSS vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. EPSS exploitation probability: 0.0%.

How to fix or mitigate CVE-2026-20430?

Within 24 hours: Identify all affected AP models in inventory and assess wireless network exposure; disable non-essential wireless services if possible. Within 7 days: Implement enhanced wireless network segmentation and client isolation; restrict AP management access to hardened jump hosts only; increase monitoring for unusual privilege escalation attempts. Within 30 days: Establish vendor contact for patch timeline and ETA; develop emergency patching procedures; consider temporary replacement hardware for highest-risk locations pending patch availability.

Openwrt CVE-2026-20430

HIGH

Out-of-bounds Write (CWE-787)

2026-03-02 security@mediatek.com

Privilege Escalation Mediatek Openwrt Software Development Kit

8.8

CVSS 3.1 · NVD

View

Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

Access

Connect to vulnerable WLAN access point
Exploit

Send crafted wireless frame
Execution

Trigger out of bounds write
Impact

Escalate privilege to AP firmware level

Vulnerability Assessment

Weakness	CWE CWE-787 OWASP Top 10:2025 A06:2021 - Vulnerable and Outdated Components ASVS 5.0 V15 - Secure Coding and Architecture Bounds checking, write limits MITRE ATT&CK 2 techniques across 2 tactics: Execution, Privilege Escalation The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. Sign in to read
Exploitation Conditions	Physical or adjacent network proximity to vulnerable WLAN AP required. Out of bounds write in WLAN AP firmware due to incomplete bounds checking in frame processing. Default AP configuration with wireless interface enabled is exploitable.
Impact	CVSS 8.8 (HIGH). Attack vector: Adjacent Network. Complexity: Low. Privileges required: None. User interaction: None. Exploitable via remote/network.
Exploit ScenarioDerived	A remote attacker could exploit this vulnerability to remote (proximal/adjacent) escalation of privilege with no additional execution.

This Week Schedule remediation this week. Why: HIGH severity (CVSS 7.0-8.9).

No patch listed yet 0.0% exploitation probability (EPSS)

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AnalysisAIv1 – Mar 12, 2026

OpenWrt and its Software Development Kit contain an out-of-bounds write vulnerability in the WLAN access point firmware caused by improper bounds checking, enabling adjacent network attackers to achieve privilege escalation without user interaction or special privileges. The vulnerability carries high severity with complete impact across confidentiality, integrity, and availability, though no patch is currently available.

Earlier versions of this analysis (1)

v1 Mar 12, 2026 - 21:55 CVSS 8.8

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. [CVSS 8.8 HIGH]

RemediationAI

Monitor vendor advisories for a patch. Enable ASLR, DEP/NX, and stack canaries where possible.

Affects your stack

Find out whether the stacks and servers you run are on an affected version.

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

Classified as CWE-787 (Out-of-bounds Write). Affects Software Development Kit. 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.

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Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

NVD PRIMARY 8.8 HIGH

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

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector

Adjacent

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

DescriptionCVE.org

Executive ViewAI

Why It Matters

A high-severity vulnerability in wireless access point firmware allows attackers within network proximity to gain elevated system privileges without additional exploits. This affects all organizations using vulnerable AP models and could enable lateral movement, data exfiltration, or network compromise from the wireless perimeter.

Business Impact: High

Compensating Controls

Implement strict wireless network segmentation using VLAN isolation; disable WPA3/WPA2 management frame protection bypass if available in firmware; restrict AP management interfaces to out-of-band networks; enable enhanced logging and SIEM alerting for AP authentication anomalies; consider disabling guest/open wireless networks until patch available; deploy rogue AP detection and client isolation policies; monitor for lateral movement attempts from wireless segments

Threat Intelligence Overview

EPSS Score

0.0%

Top 95% exploitable

Data Quality

3 sources

Confidence: Low

NVD

CVE.org

EPSS

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue

Severity HIGH

CISA KEV No

Public POC No

EPSS 0.0%

Patch available No

Active threat No

Deciding rule

HIGH severity (CVSS 7.0-8.9)

What every action level means

Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.

Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.

This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.

This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.

Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived

Scheduled

Exploitation· derived

None

System Exposure· derived

Controlled

Automatable· derived

Human Impact

High

Priority Score

Low Medium High Critical

KEV: 0

EPSS: 0

CVSS: +44

PoC: 0

Weaponized: 0

Threat intel: 0

Gov advisory: 0

Attack Technique

Privilege Escalation HIGH

Privilege escalation occurs when an attacker leverages flaws in access control mechanisms to gain permissions beyond what they were originally granted.