CVE-2026-57916

proCertum SmartSign opens Certificate Practice Statement (CPS) URI without schema validation. An attacker can prepare arbitrary certificate with CPS URI pointing to a local executable file or any URL, sign a document with it, and send it to the victim. When the victim opens the document in the application, the specified file will be executed (or webpage will be opened). This issue was fixed in version 9.4.3.90.