# CVE-2025-41700: CODESYS Development System - Deserialization of Untrusted Data

> An attacker can execute arbitrary code by tricking a user into opening a malicious project file in the CODESYS Development System.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 1 Dec 2025
- **Updated:** 1 Dec 2025
- **Also known as:** GHSA-cx2q-9f4q-7mgw

## What is CVE-2025-41700?

CVE-2025-41700 is a high-severity unsafe deserialization vulnerability in CODESYS Development System, published on 1 Dec 2025. 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

An unauthenticated attacker can trick a local user into executing arbitrary code by opening a deliberately manipulated CODESYS project file with a CODESYS development system. This arbitrary code is executed in the user context.

Weakness: CWE-502 (Deserialization of Untrusted Data)

## Which versions are affected by CVE-2025-41700?

It affects 1 product.


Products: Codesys Codesys.

## How do I fix CVE-2025-41700?

No fix has been published for CVE-2025-41700 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-41700 being exploited?

There is no known exploitation of CVE-2025-41700 in the wild and no public exploit code.

## Other vulnerabilities in CODESYS Development System

- [CVE-2019-16265](https://insights.sbomify.com/CVE-2019-16265/): Memory corruption in n/a (critical 9.8)
- [CVE-2021-34584](https://insights.sbomify.com/CVE-2021-34584/): CODESYS V2 web server: crafted requests could trigger a buffer over-read (DoS) (critical 9.1)
- [CVE-2021-21869](https://insights.sbomify.com/CVE-2021-21869/): Deserialization in CODESYS (high 8.8)
- [CVE-2021-21867](https://insights.sbomify.com/CVE-2021-21867/): Deserialization in CODESYS (high 8.8)
- [CVE-2021-21868](https://insights.sbomify.com/CVE-2021-21868/): Deserialization in CODESYS (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-41700 and fix it if it is affected.

What it is: CVE-2025-41700 is a high-severity unsafe deserialization vulnerability in CODESYS Development System, published on 1 Dec 2025. 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-2025-41700 in the wild and no public exploit code.

Affected product: CODESYS Development System. 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-2025-41700/ (Markdown: https://insights.sbomify.com/CVE-2025-41700/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-41700
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-41700
- OSV: https://osv.dev/vulnerability/CVE-2025-41700

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-41700/
Summaries are generated and may contain mistakes; the official description above is the record.