Cyber Resilience

CVE-2025-8679

High

Published: 01 October 2025

Published
01 October 2025
Modified
15 January 2026
KEV Added
Patch
CVSS Score v4 7.6 CVSS:4.0/AV:A/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0005 17.2th percentile
Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-8679 is a high-severity Improper Restriction of Excessive Authentication Attempts (CWE-307) vulnerability in Extremenetworks Extremeguest Essentials. Its CVSS base score is 7.6 (High).

Operationally, ranked at the 17.2th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

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…

more

logs may display the client MAC as the username despite no MAC-authentication being enabled.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

extremenetworks
extremeguest essentials
≤ 25.5.0

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-307

This control directly enforces limits on consecutive invalid logon attempts and automatic response (e.g., lockout) to prevent brute-force exploitation of authentication mechanisms.

addresses: CWE-307

Specific conditions can include excessive failed attempts, triggering stronger authentication that restricts brute-force exploitation.

References