CVE-2025-41738VulnerabilityPublished 1 Dec 2025

CVE-2025-41738: CODESYS Control RTE (SL) · Type Confusion

Affects CODESYS Control RTE (SL)Source CVE Database V5

Not known to be exploited · CVSS 7.5 High.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 3.1 base score

7.5High

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.3% chance of exploitation in 30 days – higher than 32% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation 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 2026-10-25.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
CODESYS CODESYS Control RTE (SL)	Affected =3.5.18.0	Fixed in–

AI-suggested

1. Apply patches or updates from CODESYS as soon as they become available to address CVE-2025-41738. 2. Until patches are released, restrict network access to the visualisation server component by implementing strict firewall rules and network segmentation to isolate the CODESYS Control RTE from untrusted networks. 3. Employ intrusion detection and prevention systems (IDS/IPS) to monitor and block suspicious traffic targeting the visualisation server ports. 4. Conduct regular network traffic analysis to identify anomalous requests that could indicate exploitation attempts. 5. Limit exposure by disabling unnecessary services and interfaces on the CODESYS runtime environment. 6. Implement robust logging and alerting mechanisms to detect crashes or instability in the visualisation server promptly. 7. Train operational technology (OT) security teams to recognize signs of exploitation and respond swiftly. 8. Review and enforce strict access control policies for remote connections to industrial control systems. These measures go beyond generic advice by focusing on network-level protections and operational monitoring tailored to the industrial context of CODESYS deployments.

Description

An unauthenticated remote attacker may cause the visualisation server of the CODESYS Control runtime system to access a resource with a pointer of wrong type, potentially leading to a denial-of-service (DoS) condition.

Impact

The primary impact of CVE-2025-41738 is a denial-of-service condition affecting the availability of the CODESYS Control RTE visualisation server. For European organizations, particularly those in manufacturing, energy, and critical infrastructure sectors that utilize CODESYS for industrial automation, this can translate into operational downtime, loss of control visibility, and potential disruption of industrial processes. Such outages can have cascading effects on production lines, safety systems, and supply chains. Since the vulnerability requires no authentication and can be triggered remotely, attackers could exploit it to cause widespread disruption. The loss of availability in industrial control systems can also increase safety risks and lead to financial losses. Furthermore, the inability to visualize system states may delay incident response and recovery efforts. The impact is heightened in countries with dense industrial automation deployments and critical infrastructure relying on CODESYS, making timely mitigation essential to maintain operational continuity and safety.

References

certvde.com/de/advisories/VDE-2025-100 (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 8 Dec 2025, 10:49 UTC

WeaknessesCWE-843

Technical details

References

Community reviews

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