Auth bypass in Ebyte Na111-M Firmware

CVE-2026-77977

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.

Vulnerability class: Broken Authentication

Published · last modified .

CVSS v3 metric

CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H.

EPSS exploit prediction

EPSS: 0.004 (28.6th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 29th percentile — 28.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-77977: held from 0.002 to 0.004.

EPSS over last 30 days · oldest: 0.002 · newest: 0.004 · change: +0.001

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-77977?
CVE-2026-77977 is a high-severity vulnerability in Ebyte Na111-M Firmware, classified under Missing Authentication for Critical Function. CVSS score: 8.1/10. Published 2026-08-28.
How severe is CVE-2026-77977?
High severity. CVSS v3 base score is 8.1 out of 10.