# CVE-2026-34223: Code injection in Desigo CC ClickOnce Client V6

> Attackers can execute arbitrary code and write files on client systems by tricking users into opening malicious graphics documents in Siemens Desigo CC clients.

- **Severity:** High 8.6 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 8 Sep 2026
- **Updated:** 14 Sep 2026
- **Also known as:** GHSA-3r86-r8f3-cmm5

## What is CVE-2026-34223?

CVE-2026-34223 is a high-severity code injection vulnerability in Siemens Desigo CC ClickOnce Client V6, published on 8 Sep 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

A vulnerability has been identified in Desigo CC ClickOnce Client V6 (All versions), Desigo CC ClickOnce Client V7 (All versions), Desigo CC family V8 (All versions), Desigo CC family V9 (All versions), Desigo CC Flex Client V6 (All versions), Desigo CC Flex Client V7 (All versions), Desigo CC Installed Client V6 (All versions), Desigo CC Installed Client V7 (All versions). The affected application is vulnerable to Client Code Execution (CCE) due to insufficient input validation when handling scripts embedded within user-defined graphics documents.  Specifically, when the script within a graphics document is designed or modified by an attacker to include malicious commands.  When a user opens a compromised graphics document, the embedded script is executed on the client application instance, allowing an attacker to write arbitrary files to the client's operating system. Successful exploitation requires an attacker to craft a malicious graphics document and entice a user with sufficient privileges to display it.  This could lead to compromise of the client operating system and potential lateral movement within the organization.

Weakness: CWE-94 (Improper Control of Generation of Code)

## Which versions are affected by CVE-2026-34223?


## How do I fix CVE-2026-34223?

No fix has been published for CVE-2026-34223 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-34223 being exploited?

There is no known exploitation of CVE-2026-34223 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-34223 and fix it if it is affected.

What it is: CVE-2026-34223 is a high-severity code injection vulnerability in Siemens Desigo CC ClickOnce Client V6, published on 8 Sep 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-34223 in the wild and no public exploit code.

Affected product: Siemens Desigo CC ClickOnce Client V6. 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-2026-34223/ (Markdown: https://insights.sbomify.com/CVE-2026-34223/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-34223
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-34223
- OSV: https://osv.dev/vulnerability/CVE-2026-34223

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-34223/
Summaries are generated and may contain mistakes; the official description above is the record.