# CVE-2018-9186: Cross-site scripting in FortiAuthenticator

> An attacker can execute unauthorized script code in FortiAuthenticator by injecting malicious scripts into the HTTP referer header on the CSRF validation failure page.

- **Severity:** Medium 6.1 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 31 May 2018
- **Updated:** 25 Oct 2024
- **Also known as:** GHSA-46pc-6g7g-6hw8

## What is CVE-2018-9186?

CVE-2018-9186 is a medium-severity cross-site scripting vulnerability in Fortinet, Inc. FortiAuthenticator, published on 31 May 2018. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

A cross-site scripting (XSS) vulnerability in Fortinet FortiAuthenticator in versions 4.0.0 to before 5.3.0 "CSRF validation failure" page allows attacker to execute unauthorized script code via inject malicious scripts in HTTP referer header.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2018-9186?

It affects 1 product.


Products: Fortinet Fortiauthenticator.

## How do I fix CVE-2018-9186?

No fix has been published for CVE-2018-9186 yet. Limit exposure of the affected software until one is available.

## Is CVE-2018-9186 being exploited?

There is no known exploitation of CVE-2018-9186 in the wild and no public exploit code.

## Other vulnerabilities in Fortinet, Inc. FortiAuthenticator

- [CVE-2026-44277](https://insights.sbomify.com/CVE-2026-44277/): Missing authorization in FortiAuthenticator (critical 9.1)
- [CVE-2013-6990](https://insights.sbomify.com/CVE-2013-6990/): Privilege escalation in n/a (critical 9.0)
- [CVE-2021-43067](https://insights.sbomify.com/CVE-2021-43067/): Information disclosure in Fortinet FortiAuthenticator (high 8.3)
- [CVE-2021-22124](https://insights.sbomify.com/CVE-2021-22124/): Denial of service in Fortinet FortiSandbox, FortiAuthenticator (high 7.5)
- [CVE-2015-1455](https://insights.sbomify.com/CVE-2015-1455/): Hardcoded credentials in n/a (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-9186 and fix it if it is affected.

What it is: CVE-2018-9186 is a medium-severity cross-site scripting vulnerability in Fortinet, Inc. FortiAuthenticator, published on 31 May 2018. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2018-9186 in the wild and no public exploit code.

Affected product: Fortinet, Inc. FortiAuthenticator. 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-2018-9186/ (Markdown: https://insights.sbomify.com/CVE-2018-9186/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-9186
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-9186
- OSV: https://osv.dev/vulnerability/CVE-2018-9186

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-9186/
Summaries are generated and may contain mistakes; the official description above is the record.