CVE-2026-20436
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 escalation of privilege due to a missing bounds check. This could lead to local escalation of privilege if a malicious actor has already obtained the System privilege. User interaction is not needed for exploitation. Patch ID: WCNCR00473802; Issue ID: MSV-5970.
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 (Station) driver allows a local attacker who already possesses System-level privileges to further escalate privileges. No user interaction is required for exploitation. The vulnerability stems from insufficient input validation in the driver code.
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
- High
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:H/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.
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Identify Mediatek Nbiot Sdk installationLocate the Mediatek Nbiot Sdk installation directory or check system packages for 'nbiot' or 'mediatek' sdk components. Use commands like 'find / -name *nbiot*' or check standard SDK installation paths.Affected if Mediatek Nbiot Sdk is found on the system
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Determine installed SDK versionCheck the SDK version by examining version files, metadata, or using SDK-specific version query commands. Common locations include version info in SDK headers, manifest files, or package manager listings.Affected if Version is 3.8 or lower (the vulnerable version range)
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Verify WLAN STA driver presenceCheck if the WLAN STA driver module is loaded or present on the system. Look for kernel modules named 'wlan_sta', 'mtk_sta', or similar in /proc/modules, or check driver binary files in the SDK drivers directory.Affected if WLAN STA driver is loaded or present in the SDK
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Check driver configurationInspect driver configuration files or settings that control WLAN STA functionality. Look for config files in the SDK that enable/disable the STA mode or check driver initialization parameters.Affected if WLAN STA driver is enabled in configuration
User is affected if Mediatek Nbiot Sdk version 3.8 or lower is installed with the WLAN STA driver enabled and loaded.
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.
From vendor dataApply the vendor patch (WCNCR00473802) to the WLAN STA driver. Since this is a driver-level vulnerability, the fix will typically be delivered as a firmware or driver update that should be tested for regressions in wireless connectivity.
- Consultation3.0 h
- Implementation2.0 h
- Testing6.0 h
- Review / QA3.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-20436 — 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-2026-20436 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
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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
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