# CVE-2026-27867: CROSS-SITE SCRIPTING (XSS) VIA THE CMDCOOKIE PARAMETER REGESTA SMART HD-PLC OF TELDAT

> An attacker can inject malicious scripts via the cmdcookie parameter in the upgrade interface, potentially executing code or bypassing security controls.

- **Severity:** Medium 4.8 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/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:** 25 Sep 2026
- **Updated:** 25 Sep 2026
- **Also known as:** GHSA-jj76-67xg-c9gj

## What is CVE-2026-27867?

CVE-2026-27867 is a medium-severity cross-site scripting vulnerability in Teldat Regesta Smart HD-PLC - TLDPH16D2, published on 25 Sep 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

An attacker with access via network to the Regesta Smart HD-PLC of the provider Teldat (in this case, registration action is required) who has the vulnerable firmware version could inject
a specific payload via the parameter "cmdcookie" withing the /upgrade/index.html resulting in to a Cross-Site Scripting (XSS). This issue affects Regesta Smart HD-PLC - TLDPH16D2: 
11.02.06.00.02

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

## Which versions are affected by CVE-2026-27867?


## How do I fix CVE-2026-27867?

No fix has been published for CVE-2026-27867 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-27867 being exploited?

There is no known exploitation of CVE-2026-27867 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-27867 and fix it if it is affected.

What it is: CVE-2026-27867 is a medium-severity cross-site scripting vulnerability in Teldat Regesta Smart HD-PLC - TLDPH16D2, published on 25 Sep 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-2026-27867 in the wild and no public exploit code.

Affected product: Teldat Regesta Smart HD-PLC - TLDPH16D2. 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-2026-27867/ (Markdown: https://insights.sbomify.com/CVE-2026-27867/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-27867
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-27867
- OSV: https://osv.dev/vulnerability/CVE-2026-27867

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-27867/
Summaries are generated and may contain mistakes; the official description above is the record.