What is the CVSS score of CVE-2026-20418?

CVE-2026-20418 has a CVSS 3.1 base score of 9.8 (Critical). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. EPSS exploitation probability: 0.1%.

Which versions of Matter are affected by CVE-2026-20418?

CVE-2026-20418 is a critical remote privilege escalation vulnerability affecting Thread with a 9.8 CVSS score and no available patch.

How to fix or mitigate CVE-2026-20418?

Within 24 hours: Identify and inventory all systems running Thread; assess exposure in production and non-production environments; establish incident response readiness. Within 7 days: Implement network segmentation to isolate Thread services; enable enhanced monitoring and logging for Thread processes; establish vendor communication channels for patch timeline. Within 30 days: Deploy compensating controls (WAF rules, input validation hardening, or service isolation); conduct penetration testing of affected systems; develop and test rollback procedures for Thread upgrades when patches become available.

Matter CVE-2026-20418

CRITICAL

Out-of-bounds Write (CWE-787)

2026-02-02 security@mediatek.com

Privilege Escalation Matter

9.8

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

9.8 CRITICAL

AV:N/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

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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Analysis Generated

Mar 12, 2026 - 22:01 vuln.today

CVE Published

Feb 02, 2026 - 09:15 nvd

CRITICAL 9.8

DescriptionCVE.org

In Thread, there is a possible out of bounds write due to a missing bounds check. This could lead to remote escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation. Patch ID: WCNCR00465153; Issue ID: MSV-4927.