CyberSecBulletin
CVE-2026-77977NVD status: Deferred

Ebyte NA111-M Firmware: Missing Authentication for Critical Functionality

Published Updated By the CyberSecBulletin desk

CVE-2026-77977 is a high-severity missing authentication for critical functionality vulnerability in Ebyte NA111-M Firmware from Ebyte, with a CVSS 3.1 base score of 8.1 out of 10. It can be exploited from the same local 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 0.37% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of Ebyte NA111-M Firmware you run against the affected versions below, and install the vendor's latest release.

Affected products and versions

VendorProductAffected versionsFixed in
EbyteEbyte NA111-M Firmware9013-2-17Not 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
AdjacentThe attacker must be on the same local network segment.
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
NoneNo data is disclosed.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H. Scored by CNA (hq.dhs.gov).

Scoring systemScoreSeverityScored by
CVSS 4.07.2HighCNA (hq.dhs.gov)
CVSS 3.18.1HighCNA (hq.dhs.gov)

Official description

Ebyte gateway product's vendor configuration utility does not require authentication before allowing certain disruptive administrative actions when default credentials remain configured. An unauthenticated attacker on the adjacent network could reboot the device or restore factory settings, resulting in a loss of configuration and service availability.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Missing Authentication for Critical Functionality

The product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources.

How developers prevent this class of flaw

  • For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, consider using libraries with authentication capabilities such as OpenSSL or the ESAPI Authenticator.
  • When storing data in the cloud (e.g., S3 buckets, Azure blobs, Google Cloud Storage, etc.), use the provider's controls to require strong authentication for users who should be allowed to access the data.

More Missing Authentication for Critical Functionality vulnerabilities (CWE-306)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in Ebyte NA111-M Firmware

All Ebyte NA111-M Firmware vulnerabilities

Recent Missing Authentication for Critical Functionality vulnerabilities

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