CVE-2026-40003
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 · uneditedZTE ZX297520V3 BootROM contains a vulnerability that allows arbitrary memory writes via USB. Attackers can exploit the lack of target address validation in the USB download mode to write data to any location in BootROM runtime memory, thereby overwriting the stack, hijacking the execution flow, bypassing the Secure Boot signature verification mechanism, and achieving unauthorized code execution.
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 · high confidenceThe ZTE ZX297520V3 BootROM has a vulnerability in its USB download mode that lacks target address validation, allowing attackers to write arbitrary data to any memory location in the BootROM runtime. This enables stack overwriting, execution flow hijacking, bypass of Secure Boot signature verification, and unauthorized code execution.
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 dataall versionsCVSS 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
- Physical
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:P/AC:L/PR:N/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 ZTE ZX297520V3 chipset usageInspect device hardware specifications, FCC filing documents, or boot logs for 'ZX297520V3' or 'ZTE' chipset identifiers. Check product datasheets or teardown reports if available.Affected if The device explicitly uses the ZTE ZX297520V3 chipset
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Verify USB download mode accessibilityCheck device documentation or settings for USB download mode, emergency download mode, or firmware upgrade ports. Look for USB OTG/DFU interfaces exposed on the device.Affected if USB download mode is exposed and accessible on the device
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Check for physical USB port exposureInspect the physical device for accessible USB ports (USB-A, USB-C, micro-USB) that could be used to trigger the USB download mode.Affected if USB ports are physically accessible without disassembly
A user is affected if their device uses the ZTE ZX297520V3 chipset and exposes USB download mode functionality that can be triggered via physical USB access.
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 vendor-supplied firmware updates if available; otherwise replace affected hardware. Implement physical access controls to prevent unauthorized USB device connections and consider hardware compartmentalization.
- Consultation8.0 h
- Implementation40.0 h
- Testing16.0 h
- Review / QA12.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $21,376.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-40003 — 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-2026-40003 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