CVE-2025-41738

ABB AC500 V3 Firmware — vulnerability CVE-2025-41738

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.

CVSS 7.5Patch available

This record: live connection— last retrieved: 7 November 2026 at 00:02.

Vendors

ABB, WAGO, CODESYS

Products

AC500 V3 Firmware, CC100, PFC100, PFC200, TP600, Edge Controller and 13 more

up to version <3.9.1

Published

1 December 2025

Last modified

17 June 2026

Original source information

Taken directly from NVD, CISA or the vendor — sometimes in English, unchanged from the source.

Technical description

CVSS 3.1 — vector details

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

Attack vector

NETWORK

Privileges required

NONE

User interaction

NONE

Confidentiality

None

Integrity

None

Availability

High

EPSS — Exploit Prediction Scoring System

Probability of exploitation within 30 days

0.4%

Percentile

36e

Source: FIRST.org, updated on 5 November 2026.

Patch information

The problem is corrected in the following product version: - AC500 V3 firmware version 3.9.1 ABB recommends that customers apply the update at earliest convenience. This firmware version is released for all AC500 V3 PLC types and integrated into Automation Builder 2.9.1. Automation Builder 2.9.1 is available for download from the related download site. https://www.abb.com/global/en/areas/motion/digital-tools/automation-builder/software-download

IACS Radar assessment

Our own interpretation and context for the source data above.

IACS Radar assessment

Our own interpretation and context for this vulnerability — not an official source.

IACS Radar priority score

46/ 100

Based on CVSS 7.5, EPSS 0.4%, industrial relevance 55/100.

Combines CVSS, EPSS, KEV status, industrial relevance and exposure relevance — a complement to, not a replacement for, the individual scores below and above.

Conditions for exploitation

•Network access to the affected device or segment is required.
•No valid credentials are needed.
•No user interaction required.

Operational impact & energy relevance

Possible loss of visibility of or control over the process upon successful exploitation.

Assessed as relevant to the energy sector based on: Vermeld in een officiële CISA ICS Advisory, wat directe relevantie voor industriële besturingssystemen bevestigt. Vendor "ABB" is a known supplier of equipment for the energy sector.

Recommended defensive measures

•Apply the latest firmware or software update and validate its integrity.
•Restrict network access to the affected device to a dedicated OT management segment.
•Implement network segmentation in line with zones and conduits (IEC 62443-3-2).
•Monitor for abnormal protocol traffic using an OT-aware detection system.

Industrial relevance score

55/ 100

• Mentioned in an official CISA ICS advisory, which confirms direct relevance to industrial control systems.
• Vendor "ABB" is a known supplier of equipment for the energy sector.

Classification is provisional; manual verification by an OT security analyst is recommended.

Classified by IACS Radar-analysepijplijn (geautomatiseerd) on 7 November 2026.

IEC 62443 mapping

IEC 62443-4-1FR3 · Systeemintegriteit

Automatic IACS Radar assessment based on the reported CWE weakness classification; not an official certification statement.

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