Unauthorized Access Flaw in Extreme Networks' ExtremeGuest Essentials
CVE-2025-8679

7.6HIGH

Key Information:

Vendor
CVE Published:
1 October 2025

What is CVE-2025-8679?

A vulnerability exists in Extreme Networks' ExtremeGuest Essentials versions prior to 25.5.0, where the captive portal may allow unauthorized access. This occurs during specific configurations of the captive portal SSID, where repeated manual login attempts can lead an unauthenticated device to be falsely recognized as authenticated, thereby gaining access to the network. Notably, Client360 logs may display the MAC address of the client as the username, despite the absence of MAC-authentication practices. This significant flaw highlights the importance of securing guest network access to prevent unauthorized entry.

Affected Version(s)

ExtremeGuest Essentials 25.4.0

References

CVSS V4

Score:
7.6
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
None
Attack Vector:
Adjacent Network
Attack Complexity:
High
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

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CVE-2025-8679 : Unauthorized Access Flaw in Extreme Networks' ExtremeGuest Essentials