# CVE-2025-8679: ExtremeGuest Essentials Captive Portal Unauthenticated Brute Force

> Unauthenticated attackers can bypass captive portal authentication via brute force under specific SSID configurations, gaining unauthorized network access.

- **Severity:** High 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`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 1 Oct 2025
- **Updated:** 1 Oct 2025
- **Also known as:** GHSA-pwmr-hpc5-jq8r

## What is CVE-2025-8679?

CVE-2025-8679 is a high-severity authentication bypass vulnerability in ExtremeGuest Essentials, published on 1 Oct 2025. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

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.

Weakness: CWE-307 (Improper Restriction of Excessive Authentication Attempts)

## Which versions are affected by CVE-2025-8679?

It affects 1 product.


Products: Extremenetworks Extremeguest Essentials.

## How do I fix CVE-2025-8679?

No fix has been published for CVE-2025-8679 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-8679 being exploited?

There is no known exploitation of CVE-2025-8679 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-8679 and fix it if it is affected.

What it is: CVE-2025-8679 is a high-severity authentication bypass vulnerability in ExtremeGuest Essentials, published on 1 Oct 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-8679 in the wild and no public exploit code.

Affected product: ExtremeGuest Essentials. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2025-8679/ (Markdown: https://insights.sbomify.com/CVE-2025-8679/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-8679
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-8679
- OSV: https://osv.dev/vulnerability/CVE-2025-8679

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-8679/
Summaries are generated and may contain mistakes; the official description above is the record.