CVE-2025-8679: In ExtremeGuest Essentials before 25.5.0, captive-portal may permit unauthorized access via manual brute-force

Q: How do I fix CVE-2025-8679?

extremeguest essentials: upgrade to 25.5.0. Exact commands for each OS are on this page.

Q: Is CVE-2025-8679 being exploited?

CVE-2025-8679 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2025-8679 affect?

CVE-2025-8679 affects extremeguest essentials. Severity is critical (CVSS 9.8). 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

Q: How urgent is CVE-2025-8679?

Priority 46/100. Critical severity; Remotely exploitable, no login, no user action

This month

CRITICAL 9.8REMOTEUPGRADE

CVE-2025-8679 is a critical-severity flaw (CVSS 9.8) affecting extremeguest essentials. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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.

Why this priority

Critical severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.3% (top 73%)
CISA exploited list	No
Weakness	CWE-307
Published	2025-10-01
Last modified	2026-10-12

Publisher (CNA): ExtremeNetworks · Vendor: extremenetworks

Last updated 2026-10-12 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2025-10-01 18:15 UTCPublished CVE record published
2026-10-12 15:10 UTCUpdated Record last modified

extremenetworks extremeguest essentials UPGRADE

Affected: < 25.5.0

Fixed in: 25.5.0

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy extremeguest-essentials || rpm -q extremeguest-essentials || extremeguest-essentials --version

2. UPGRADE to 25.5.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade extremeguest-essentials

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade extremeguest-essentials

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2025-8679?

extremeguest essentials: upgrade to 25.5.0. Exact commands for each OS are on this page.

Is CVE-2025-8679 being exploited?

CVE-2025-8679 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2025-8679 affect?

CVE-2025-8679 affects extremeguest essentials. Severity is critical (CVSS 9.8). 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

How urgent is CVE-2025-8679?

Priority 46/100. Critical severity; Remotely exploitable, no login, no user action

References

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