ACE vulnerability in conditional configuration file processing by QOS.CH logback-core up to and including version 1.5.34 in Java applications, allows an attacker to execute arbitrary code circumventing existing protections against CVE-2025-11226 by compromising an existing logback configuration file or by injecting an environment variable before program execution.



A successful attack requires the presence of Janino library to be present on the user's class path. In addition, the attacker must  have write access to a
configuration file. Alternatively, the attacker could inject a malicious
environment variable pointing to a malicious configuration file. In both
cases, the attack requires existing privilege.