CVE-2025-41700: CODESYS Development System · Deserialization of Untrusted Data
Affects CODESYS Development SystemSource CVE Database V5
Not known to be exploited · CVSS 7.8 High.
Data as of 26 Oct 2026, 06:26 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 4% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 1 Dec 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-26.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| CODESYS CODESYS Development System | Affected
| Fixed in– |
AI-suggested
Until an official patch is released, European organizations should implement strict controls on the handling of CODESYS project files. This includes educating users to avoid opening project files from untrusted or unknown sources and implementing application whitelisting to restrict execution of unauthorized code. Network segmentation should isolate engineering workstations from broader corporate and operational networks to limit lateral movement if compromise occurs. Employ endpoint detection and response (EDR) solutions to monitor for suspicious deserialization or code execution behaviors. Regular backups of project files and system states should be maintained to enable recovery from potential compromise. Additionally, organizations should engage with CODESYS vendors and subscribe to security advisories to promptly apply patches once available. Implementing file integrity monitoring on project directories and enforcing strict access controls can further reduce risk. Finally, consider sandboxing or virtualizing engineering environments to contain potential exploitation.
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.