# CVE-2026-23756: GFI HelpDesk < 4.99.9 Stored XSS via Troubleshooter Step Subject

> An authenticated staff member can inject arbitrary JavaScript into the Troubleshooter step subject, leading to stored XSS when viewed by other users.

- **Severity:** Medium 5.1 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 20 Apr 2026
- **Updated:** 1 Oct 2026
- **Also known as:** GHSA-99wh-5v8j-65hf

## What is CVE-2026-23756?

CVE-2026-23756 is a medium-severity cross-site scripting vulnerability in GFI Software HelpDesk, published on 20 Apr 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

GFI HelpDesk before 4.99.9 contains a stored cross-site scripting vulnerability in the Troubleshooter module where the subject POST parameter is not sanitized in Controller_Step.InsertSubmit() and EditSubmit() before being rendered by View_Step.RenderViewSteps(). An authenticated staff member can inject arbitrary JavaScript into the step subject field, and the payload executes when any user navigates to Troubleshooter > View Troubleshooter and clicks the affected step link.

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

## Which versions are affected by CVE-2026-23756?

It affects 1 product.


Products: Gfi Helpdesk.

## How do I fix CVE-2026-23756?

No fix has been published for CVE-2026-23756 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-23756 being exploited?

There is no known exploitation of CVE-2026-23756 in the wild and no public exploit code.

## Other vulnerabilities in GFI Software HelpDesk

- [CVE-2026-23757](https://insights.sbomify.com/CVE-2026-23757/): GFI HelpDesk < 4.99.10 Stored XSS via Reports Module (medium 5.1)
- [CVE-2026-23758](https://insights.sbomify.com/CVE-2026-23758/): GFI HelpDesk < 4.99.9 Stored XSS via editsubject Parameter (medium 5.1)
- [CVE-2026-23752](https://insights.sbomify.com/CVE-2026-23752/): GFI HelpDesk < 4.99.9 Stored XSS via companyname Parameter (medium 4.8)
- [CVE-2026-23753](https://insights.sbomify.com/CVE-2026-23753/): GFI HelpDesk < 4.99.9 Stored XSS via charset Parameter (medium 4.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-23756 and fix it if it is affected.

What it is: CVE-2026-23756 is a medium-severity cross-site scripting vulnerability in GFI Software HelpDesk, published on 20 Apr 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-23756 in the wild and no public exploit code.

Affected product: GFI Software HelpDesk. 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-2026-23756/ (Markdown: https://insights.sbomify.com/CVE-2026-23756/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-23756
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-23756
- OSV: https://osv.dev/vulnerability/CVE-2026-23756

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-23756/
Summaries are generated and may contain mistakes; the official description above is the record.