Siemens LOGO! Soft Comfort Hardcoded Cryptographic Key and Unsalted Password Hash Vulnerabilities

Technical Analysis

CVE-2026-57262 (CVSS 3.1: 6.8, CWE-321) results from use of a static, hardcoded AES master key embedded in the application to encrypt project files, allowing a local attacker to extract the key from application files or memory and decrypt project data or strip passwords without knowledge of the original password. CVE-2026-57263 (CVSS 3.1: 6.8, CWE-759) stems from storing project passwords as unsalted SHA-256 hashes, enabling efficient offline dictionary or brute-force attacks once a project file is obtained. Both vulnerabilities require local access and no user interaction, with high confidentiality impact but limited integrity impact per the CVSS vector (AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N). Exploitation could expose or modify PLC programming logic and configuration data, impacting industrial process integrity in commercial facilities and transportation sector deployments. This is an OT/ICS engineering-software vulnerability with no direct AI agent, LLM, or RAG pipeline impact, as it does not involve credential exposure to agent-accessible systems or components commonly integrated into agentic AI infrastructure.

Affected Systems

Siemens LOGO! Soft Comfort versions prior to V9 (all versions < V9); requires hardware upgrade to LOGO! V9 BM or later to fully remediate, as older hardware causes compatibility mode where vulnerabilities persist.

Indicators of Compromise

• No specific IOCs published; vulnerability is design-level (hardcoded key/unsalted hash), not tied to observed exploitation artifacts.

Remediation Steps

1. 1

   Update to LOGO! Soft Comfort V9 or later

   Apply the vendor-released update to V9 or later to remediate the hardcoded key and unsalted hash issues.

2. 2

   Upgrade hardware to LOGO! V9 BM or later

   A hardware upgrade is required in addition to the software update; otherwise the device may run in compatibility mode where the vulnerabilities remain present.

3. 3

   Restrict local access

   Limit local/physical access to engineering workstations running LOGO! Soft Comfort, as both vulnerabilities require local attacker access.

4. 4

   Network segmentation

   Isolate control system networks and engineering workstations behind firewalls, separate from business networks and the internet, per CISA ICS recommended practices.

5. 5

   Secure remote access

   If remote access is necessary, use VPNs kept up to date, recognizing that VPN security depends on the security of connected endpoints.

6. 6

   Protect project files

   Treat exported project files as sensitive assets; limit distribution and storage access to reduce exposure to offline password-cracking attempts.