What’s Vulnerable › Vulnerabilities

CVE-2026-1225: Malicious logback.xml configuration file allows instantiation of arbitrary classes

• Severity: low (CVSS 1.8 v4.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-01-22 · updated 2026-06-17
• Weakness: CWE-20

Description

ACE vulnerability in configuration file processing by QOS.CH logback-core up to and including version 1.5.24 in Java applications, allows an attacker to instantiate classes already present on the class path by compromising an existing logback configuration file. The instantiation of a potentially malicious Java class requires that said class is present on the user's class-path. In addition, the attacker must have write access to a configuration file. However, after successful instantiation, the instance is very likely to be discarded with no further ado.

Affected products

• QOS.CH Sarl Logback-core: from 0.9.20 through 1.5.24

References

• https://logback.qos.ch/news.html#1.5.25

Get alerted when CVE-2026-1225 or the next vulnerability affects your stack