CVE-2026-13006: qos.ch sarl logback-core Improper Input Validation

Vulnerability summary

CVE-2026-13006 is a high (CVSS 7.0) Improper Input Validation vulnerability in qos.ch sarl logback-core. EPSS estimates a 0.18% chance of exploitation in the next 30 days, higher than 6.5% of scored vulnerabilities.

Timeline

1. 24-06-2026
   PublishedVulnerability first disclosed.
2. 01-07-2026
   Last modifiedVulnerability information updated.

Description

ACE vulnerability in conditional configuration file processing by QOS.CH logback-core up to and including version 1.5.36 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. Please note that in logack version 1.5.37 conditional processing using Janino was removed.

• CWE-20Improper Input ValidationThe product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.