# CVE-2026-8047: CODESYS Control out-of-bounds write in CmpWebServer

Source: https://junglewise.ai/threats/cve-2026-8047-codesys-control-out-of-bounds-write-in-cmpwebserver  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-05-26. Updated: 2026-05-26  
License: CC BY 4.0 with a link back

CVE-2026-8047 · Severity: high · CVSS 7.5 · Published 2026-05-26

A vulnerability exists in the web server component of CODESYS Control, a software suite used to manage industrial automation and control systems. An attacker can send a malicious web request to crash the system, leading to a complete shutdown of industrial processes and monitoring tools. This could result in operational downtime and loss of control over connected machinery until the system is manually restarted.

Vendors: [CODESYS](https://junglewise.ai/threats/vendors/codesys).

## Quick answers

**Is CVE-2026-8047 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-8047 being exploited in the wild.

**How severe is CVE-2026-8047?** High severity, with a CVSS score of 7.5, published 26 May 2026.

**Which products and versions are affected?** CODESYS Control for Linux SL 4.15.0.0 to 4.21.0.0; CODESYS Control for Raspberry Pi SL 4.15.0.0 to 4.21.0.0; CODESYS Control RTE (SL) 3.5.21.0 to 3.5.22.20; CODESYS Control Win (SL) 3.5.21.0 to 3.5.22.20; and 1 more.

**Is there a fix for CVE-2026-8047?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-8047 attacked?** It is attacked over the network, in an operating system.

**Am I affected by CVE-2026-8047?** Check whether you run CODESYS Control for Linux SL, CODESYS Control for Raspberry Pi SL, CODESYS Control RTE (SL) or one of the others listed at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The vulnerability is an out-of-bounds write (CWE-1284) within the CmpWebServer component of the CODESYS Control Runtime. It is caused by improper length validation when parsing incoming HTTP requests. An unauthenticated remote attacker can exploit this by sending a specially crafted HTTP request to the device. Successful exploitation results in a system crash and denial of service. The vulnerability only affects systems where the Web Visualization feature is enabled and the web server is active. Patches are available for several versions, with others expected in June 2026.

## Affected products

- CODESYS Control RTE (SL) 3.5.21.0 to 3.5.22.20
- CODESYS Control Win (SL) 3.5.21.0 to 3.5.22.20
- CODESYS Control for Linux SL 4.15.0.0 to 4.21.0.0
- CODESYS Control for Raspberry Pi SL 4.15.0.0 to 4.21.0.0
- CODESYS HMI (SL) 3.5.21.0 to 3.5.22.20

## Timeline

- 2026-05-26: disclosed
- 2026-05-26: advisory

## References

- [https://www.certvde.com/en/advisories/VDE-2026-057/](https://www.certvde.com/en/advisories/VDE-2026-057/)