Ebyte NA111-M Firmware: Use of Client-Side Authentication
CVE-2026-71187 is a critical-severity use of client-side authentication vulnerability in Ebyte NA111-M Firmware from Ebyte, 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 Ebyte NA111-M Firmware versions: 9013-2-17. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.78% chance of exploitation within 30 days, higher than 57% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of Ebyte NA111-M Firmware 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 |
|---|---|---|---|
| Ebyte | Ebyte NA111-M Firmware | 9013-2-17 | 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 | 9.3 | Critical | CNA (hq.dhs.gov) |
| CVSS 3.1 | 9.8 | Critical | CNA (hq.dhs.gov) |
Official description
The Ebyte device relies on client side authentication logic that can be reproduced by unauthenticated users. An attacker may generate valid authentication requests and bypass authentication to obtain administrative access to the device.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Use of Client-Side Authentication
A client/server product performs authentication within client code but not in server code, allowing server-side authentication to be bypassed via a modified client that omits the authentication check.
How developers prevent this class of flaw
- Do not rely on client side data. Always perform server side authentication.
More Use of Client-Side Authentication vulnerabilities (CWE-603)
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 Ebyte NA111-M Firmware
- 8.8 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 8.1 High severity
- 7.5 High severity
- 9.8 Critical severity
Recent Use of Client-Side Authentication vulnerabilities
- 7.5 High severity
- 8.7 High severity
- 8.4 High severity
- 7.8 High severity
- 9.8 Critical severity
- 8.8 High severity
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