CVE-2021-40026
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 · uneditedThere is a Heap-based buffer overflow vulnerability in the AOD module in smartphones. Successful exploitation of this vulnerability may affect service integrity.
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 · low confidenceHeap-based buffer overflow vulnerability in the AOD (Always On Display) module of smartphones. The vulnerability occurs when the AOD module improperly handles memory allocation on the heap, allowing an attacker to overflow allocated buffers and potentially corrupt adjacent memory structures, leading to service integrity impact.
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< 2.0= 11.0.0= 12.0.0= 4.0.0CVSS 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
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- High
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
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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Check your HarmonyOS versionGo to Settings > About Phone > Version on your Huawei device. Look for the HarmonyOS version number.Affected if The version is less than 2.0 (for example, 1.x versions)
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Check your EMUI versionGo to Settings > About Phone > Version on your Huawei device. Look for the EMUI version number.Affected if The version equals 11.0.0 or 12.0.0
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Check your Magic UI versionGo to Settings > About Phone > Version on your Honor device running Magic UI. Look for the Magic UI version number.Affected if The version equals 4.0.0
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Verify if AOD is enabledGo to Settings > Display > Always On Display (or Settings > Lock screen > Always On Display) and check if the AOD feature is turned ON.Affected if AOD is currently enabled on the device
Your device is affected if it runs HarmonyOS below 2.0, EMUI 11.0.0 or 12.0.0, or Magic UI 4.0.0, AND the AOD feature is enabled.
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 · scoped2.0
Apply vendor-provided firmware/security updates for affected smartphone models. Until a patch is available, monitor vendor security advisories and consider disabling AOD functionality as a temporary risk mitigation.
HarmonyOS 2.0 or later; EMUI and Magic UI latest available versions
- Check the current HarmonyOS, EMUI, or Magic UI version on the device via Settings > About Phone
- For HarmonyOS devices: Upgrade to HarmonyOS 2.0 or later through Settings > System & Updates > Software Update
- For EMUI devices: Apply the latest available security update via Settings > System & Updates > Software Update
- For Magic UI devices: Apply the latest available update via Settings > System & Updates > Software Update
- After updating, verify the AOD (Always On Display) functionality works normally
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation10.0 h
- Implementation20.0 h
- Testing12.0 h
- Review / QA6.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $13,568.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-40026 — 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-2021-40026 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
- No spam, self-promotion, credentials, or personal data