# CVE-2026-108108: PHPNuxBill through 2025.3.20 CHAP Authentication Bypass via Password::chap_verify()

> Attackers can bypass CHAP authentication in PHPNuxBill to access customer accounts and consume their network plans using any incorrect password.

- **Severity:** High 7.1 (`CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:L/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:** 9 Oct 2026
- **Updated:** 14 Oct 2026
- **Also known as:** GHSA-84mc-cxq8-4h6r

## What is CVE-2026-108108?

CVE-2026-108108 is a high-severity authentication bypass vulnerability in hotspotbilling phpnuxbill, published on 9 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

PHPNuxBill through 2025.3.20 contains an authentication bypass vulnerability in RADIUS CHAP verification because Password::chap_verify() returns true when the supplied response does not match. Attackers who know a valid customer or PPPoE username can log in through MikroTik hotspot or PPPoE CHAP with any incorrect password to obtain network access and consume that customer's plan.

Weakness: CWE-287 (Improper Authentication)

## Which versions are affected by CVE-2026-108108?


## How do I fix CVE-2026-108108?

No fix has been published for CVE-2026-108108 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-108108 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-108108 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-108108 and fix it if it is affected.

What it is: CVE-2026-108108 is a high-severity authentication bypass vulnerability in hotspotbilling phpnuxbill, published on 9 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-108108 exists.

Affected product: hotspotbilling phpnuxbill. 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-2026-108108/ (Markdown: https://insights.sbomify.com/CVE-2026-108108/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-108108
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-108108
- OSV: https://osv.dev/vulnerability/CVE-2026-108108

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-108108/
Summaries are generated and may contain mistakes; the official description above is the record.