In CodeMeter Runtime before versions 8.41a and 9.10, the logger does not sanitize input strings in certain cases, allowing an attacker to inject printf-style format specifiers. This can be used to reliably crash CodeMeter and disclose sensitive information such as process memory and stack canaries. The attack works locally, for example by using cmu --set-proxy to set the proxy value, and remotely when combined with CVE-2026-81573 by setting General.ProxyServer and then triggering this vulnerability.