What is CVE-2025-0890?

CVE-2025-0890 is a critical-severity vulnerability in Zyxel Sbg3300-N000, classified under Improper Authentication. CVSS score: 9.8/10. Published 2025-02-04.

How severe is CVE-2025-0890?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Is CVE-2025-0890 known to be exploited?

2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Auth bypass in Zyxel Sbg3300-N000

CVE-2025-0890

**UNSUPPORTED WHEN ASSIGNED** Insecure default credentials for the Telnet function in the legacy DSL CPE Zyxel VMG4325-B10A firmware version 1.00(AAFR.4)C0_20170615 could allow an attacker to log in to the management interface if the administrators have the option to change the default credentials but fail to do so.

Vulnerability class: Broken Authentication

Published 2025-02-04 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.135 (96.3th percentile), scored 2026-09-29.

Moderate probability of exploitation in the next 30 days — watch for active exploitation reports. 96th percentile — 96.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.135 · newest: 0.135 · change: 0.000

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for… (vendor-advisory, Vendor Advisory)

Frequently asked questions

What is CVE-2025-0890?: CVE-2025-0890 is a critical-severity vulnerability in Zyxel Sbg3300-N000, classified under Improper Authentication. CVSS score: 9.8/10. Published 2025-02-04.
How severe is CVE-2025-0890?: Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2025-0890 known to be exploited?: 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.