Smart Doorbell X3: Use of Hard-coded Cryptographic Key
CVE-2026-28742 is a critical-severity use of hard-coded cryptographic key vulnerability in Smart Doorbell X3 from Naxclow, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Smart Doorbell X3 versions: All. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.33% chance of exploitation within 30 days, which is low compared with other CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of Smart Doorbell X3 you run against the affected versions below, and install the vendor's latest release.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Naxclow | Smart Doorbell X3 | All | Not stated |
| Naxclow | X Smart Home | All | Not stated |
| Naxclow | V720 | All | Not stated |
| Naxclow | ix cam | All | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (hq.dhs.gov).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 9.2 | Critical | CNA (hq.dhs.gov) |
| CVSS 3.1 | 9.8 | Critical | CNA (hq.dhs.gov) |
Official description
Naxclow devices use a uniform request-signing scheme based on a hard-coded, platform-wide salt embedded in every firmware image. Once this salt is recovered from any device, an attacker can generate valid signatures for arbitrary device or account operations due to the absence of per-device keys, server-side nonce tracking, or replay protections. Combined with the system’s use of plain HTTP for control-plane traffic, the construction enables broad request forgery and impersonation across the platform.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Use of Hard-coded Cryptographic Key
The product uses a hard-coded, unchangeable cryptographic key.
How developers prevent this class of flaw
- Prevention schemes mirror that of hard-coded password storage.
More Use of Hard-coded Cryptographic Key vulnerabilities (CWE-321)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other references
Other vulnerabilities in Smart Doorbell X3
- 7.5 High severity
- 8.1 High severity
- 8.8 High severity
Recent Use of Hard-coded Cryptographic Key vulnerabilities
- 8.5 High severity
- 8.7 High severity
- 8.7 High severity
- 8.1 High severity
- 9.1 Critical severity
- 8.3 High severity
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