# CVE-2026-23758: GFI HelpDesk < 4.99.9 Stored XSS via editsubject Parameter

> Authenticated staff can inject malicious JavaScript via the ticket subject field, leading to arbitrary code execution 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-rf6c-2qc7-c945

## What is CVE-2026-23758?

CVE-2026-23758 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 ticket subject field that allows authenticated staff members to inject malicious JavaScript by manipulating the editsubject POST parameter. Attackers can inject XSS payloads through inadequate sanitization in Controller_Ticket.EditSubmit() that bypass the incomplete SanitizeForXSS() method to execute arbitrary JavaScript when other staff members or administrators view the affected ticket.

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

## Which versions are affected by CVE-2026-23758?

It affects 1 product.


Products: Gfi Helpdesk.

## How do I fix CVE-2026-23758?

No fix has been published for CVE-2026-23758 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-23758 being exploited?

There is no known exploitation of CVE-2026-23758 in the wild and no public exploit code.

## Other vulnerabilities in GFI Software HelpDesk

- [CVE-2026-23756](https://insights.sbomify.com/CVE-2026-23756/): GFI HelpDesk < 4.99.9 Stored XSS via Troubleshooter Step Subject (medium 5.1)
- [CVE-2026-23757](https://insights.sbomify.com/CVE-2026-23757/): GFI HelpDesk < 4.99.10 Stored XSS via Reports Module (medium 5.1)
- [CVE-2026-23752](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-2026-23758 and fix it if it is affected.

What it is: CVE-2026-23758 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-2026-23758 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-2026-23758/ (Markdown: https://insights.sbomify.com/CVE-2026-23758/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-23758
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-23758
- OSV: https://osv.dev/vulnerability/CVE-2026-23758

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-23758/
Summaries are generated and may contain mistakes; the official description above is the record.