CVE-2026-20423
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 · uneditedIn 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.
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 confidenceA missing bounds check in the wlan STA driver allows an out-of-bounds write, enabling local privilege escalation from user-level execution to elevated privileges without requiring user interaction.
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<= 3.8CVSS 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
- Local
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:L/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 checksWork through these to decide whether this CVE applies to you.
-
Identify Mediatek NBIOT SDK installationLocate any Mediatek NBIOT SDK components or development files on the system. Search for SDK-related directories, libraries, or development packages.Affected if The Mediatek NBIOT SDK is present on the system
-
Determine SDK versionExamine SDK version information in installed files, build artifacts, or SDK metadata. Compare the found version against the affected range.Affected if The SDK version is 3.8 or lower
-
Verify wlan STA driver presenceCheck for the presence of the wlan STA driver component within the SDK or system. Look for driver files, modules, or libraries associated with the wireless STA functionality.Affected if The wlan STA driver is present and loaded
-
Confirm driver is activeInspect system processes, running services, or active network components to verify the wlan STA driver is currently executing or available for use.Affected if The wlan STA driver is active or accessible for user-level execution
If the Mediatek NBIOT SDK version 3.8 or lower is installed and the wlan STA driver is present and operational, the environment is affected by this privilege escalation vulnerability.
Generated from the published advisory. Verify against your own configuration.
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 · scopedApply vendor patch WCNCR00465314 to update the wlan STA driver and remediate the missing bounds check vulnerability.
Nbiot Sdk > 3.8 (contact MediaTek for exact version number containing the fix)
- Contact MediaTek directly (via corp.mediatek.com or your MediaTek support channel) to request the patch WCNCR00465314 for issue MSV-4956
- Apply the vendor-provided patch for the wlan STA driver out-of-bounds write vulnerability
- Verify the patch was applied successfully by checking the driver version or build timestamp
- Reboot the affected device to ensure the patched driver is loaded
- If a patched SDK version > 3.8 is available from MediaTek, upgrade to that version as the definitive fix
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation2.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,984.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-20423 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-20423 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
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.
- 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