This vulnerability (CVE-2026-24349) affects Siemens SIMATIC WinCC Unified PC Runtime versions 16, 17, 18, 19, 20, and versions of 21 before Update 2. It is classified under CWE-313 for cleartext storage in a file or on disk. The WinCC Certificate Manager does not sufficiently protect key material, potentially allowing an attacker with local access to retrieve sensitive cryptographic keys. The CVSS 3.1 base score is 7.1, indicating high severity, with an attack vector limited to local access, low attack complexity, no privileges required, and no user interaction needed. The confidentiality impact is high, while integrity and availability impacts are none. No official fix or patch has been documented as of the publication date.

An attacker with local access to the affected system could extract sensitive cryptographic key material stored in cleartext by the WinCC Certificate Manager. This compromises confidentiality of key material, potentially undermining the security of communications or authentication mechanisms relying on these keys. There is no indication of impact on system integrity or availability. No known exploits have been reported in the wild.

Patch status is not yet confirmed — check the Siemens vendor advisory for current remediation guidance. Until an official fix is released, restrict local access to affected systems to trusted personnel only and monitor for unauthorized access attempts. Avoid storing sensitive key material on affected versions without additional protective controls. Siemens has not provided an official remediation level or patch as of the publication date.