Vulnerability in Extreme Networks Extremeguest Essentials

CVE-2025-8679

In ExtremeGuest Essentials before 25.5.0, captive-portal may permit unauthorized access via manual brute-force procedure. Under certain ExtremeGuest Essentials captive-portal SSID configurations, repeated manual login attempts may allow an unauthenticated device to be marked as authenticated and obtain network access. Client360 logs may display the client MAC as the username despite no MAC-authentication being enabled.

Published · last modified .

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: 0.003 (24.8th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 25th percentile — 24.8% 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-2025-8679: held from 0.003 to 0.003.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: +0.000

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-8679?
CVE-2025-8679 is a critical-severity vulnerability in Extreme Networks Extremeguest Essentials, classified under Improper Restriction of Excessive Authentication Attempts. CVSS score: 9.8/10. Published 2025-10-01.
How severe is CVE-2025-8679?
Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2025-8679 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.