# CVE-2019-25311: thesystem Persistent XSS

> Attackers can inject malicious scripts via multiple input fields in thesystem, leading to arbitrary JavaScript execution in victim browsers.

- **Severity:** Medium 5.1 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/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:** 11 Feb 2026
- **Updated:** 11 Feb 2026
- **Also known as:** GHSA-9qqr-wpm4-gqc3

## What is CVE-2019-25311?

CVE-2019-25311 is a medium-severity cross-site scripting vulnerability in kostasmitroglou thesystem, published on 11 Feb 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

thesystem version 1.0 contains a persistent cross-site scripting vulnerability that allows attackers to inject malicious scripts through multiple server data input fields. Attackers can submit crafted script payloads in operating_system, system_owner, system_username, system_password, system_description, and server_name parameters to execute arbitrary JavaScript in victim browsers.

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

## Which versions are affected by CVE-2019-25311?

It affects 1 product.


Products: Kostasmitroglou Thesystem.

## How do I fix CVE-2019-25311?

No fix has been published for CVE-2019-25311 yet. Limit exposure of the affected software until one is available.

## Is CVE-2019-25311 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2019-25311 exists.

## Other vulnerabilities in kostasmitroglou thesystem

- [CVE-2019-25441](https://insights.sbomify.com/CVE-2019-25441/): thesystem 1.0 Command Injection via run_command endpoint (critical 9.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-25311 and fix it if it is affected.

What it is: CVE-2019-25311 is a medium-severity cross-site scripting vulnerability in kostasmitroglou thesystem, published on 11 Feb 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2019-25311 exists.

Affected product: kostasmitroglou thesystem. 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-2019-25311/ (Markdown: https://insights.sbomify.com/CVE-2019-25311/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-25311
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-25311
- OSV: https://osv.dev/vulnerability/CVE-2019-25311

---
From sbomify Insights: https://insights.sbomify.com/CVE-2019-25311/
Summaries are generated and may contain mistakes; the official description above is the record.