What is CVE-2026-20418?

CVE-2026-20418 is a critical-severity vulnerability in Google Matter, classified under Out-of-bounds Write. CVSS score: 9.8/10. Published 2026-02-02.

How severe is CVE-2026-20418?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Buffer overflow in Google Matter

CVE-2026-20418

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.

Vulnerability class: Buffer Overflow

EPSS: 0.003 (25.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Google Matter
Mediatek Mt7931
Mediatek Mt7933
Mediatek, Inc. Mediatek Chipset — versions MT7931, MT7933

Weakness classification (CWE)

CWE-787 — Out-of-bounds Write

References

security@mediatek.com (Vendor Advisory)

Frequently asked questions

What is CVE-2026-20418?: CVE-2026-20418 is a critical-severity vulnerability in Google Matter, classified under Out-of-bounds Write. CVSS score: 9.8/10. Published 2026-02-02.
How severe is CVE-2026-20418?: Critical severity. CVSS v3 base score is 9.8 out of 10.