Reference material — not professional advice. Test in staging, back up first, verify against your specific version. Use your own judgment for your environment.
● High · CVSS 7.8

How to Fix CVE-2026-20423: MediaTek chipset (Bundle Sibling)

By Sai Kiran Pandrala. Last verified: 2026-05-25.

CVE-2026-20423 is a sibling vulnerability in the same vendor advisory as CVE-2026-20416. Apply the same patched build and you close both. The technical detail below is what differs.

⚡ At a glance
Severity7.8 (High)
Actively exploited?No public listing in CISA KEV
AffectedMediaTek chipset MT7902; MediaTek chipset MT7920; MediaTek chipset MT7921; MediaTek chipset MT7922; MediaTek chipset MT7925; MediaTek chipset MT7927
Fixed inSame patched build as CVE-2026-20416
Type (CWE)CWE-749 Exposed Dangerous Method or Function

What's different about CVE-2026-20423?

In wlan STA driver, there is a possible out of bounds write due to a missing bounds check. This could lead to local escalation of privilege with User execution privileges needed. User interaction is not needed for exploitation. Patch ID: WCNCR00465314; Issue ID: MSV-4956.

How to fix CVE-2026-20423

Apply the patched build per the primary write-up: How to Fix CVE-2026-20416. All commands, verification steps, and rollback notes for MediaTek chipset are listed there.

Frequently asked questions

Does the CVE-2026-20416 patch close CVE-2026-20423?

Yes. Both CVEs are addressed by the same vendor patch. Applying the patched build closes the full bundle.

Is CVE-2026-20423 listed in CISA KEV?

No public KEV listing at the time of this writing.

Where is the official advisory?

See https://corp.mediatek.com/product-security-bulletin/March-2026

References


*Written by Sai Kiran Pandrala. Part of the MediaTek chipset bundle. Full procedure at how-to-fix-cve-2026-20416.*