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.
Advisories

No advisories yet.

Fixes

Solution

Update to logback version 1.5.25 or later.


Workaround

No workaround given by the vendor.

References
History

Fri, 23 Jan 2026 00:15:00 +0900

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Thu, 22 Jan 2026 21:30:00 +0900

Type Values Removed Values Added
Title Conditional processing of logback.xml configuration file, in conjuction with Spring Framework and Janino Malicious logback.xml configuration file allows instantiation of arbitrary classes

Thu, 22 Jan 2026 18:45:00 +0900

Type Values Removed Values Added
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.
Title Conditional processing of logback.xml configuration file, in conjuction with Spring Framework and Janino
Weaknesses CWE-20
References
Metrics cvssV4_0

{'score': 1.8, 'vector': 'CVSS:4.0/AV:L/AC:H/AT:P/PR:H/UI:N/VC:L/VI:L/VA:L/SC:L/SI:L/SA:L/S:N/AU:N/RE:M/U:Green'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: NCSC.ch

Published:

Updated: 2026-01-22T14:14:17.842Z

Reserved: 2026-01-20T12:29:25.357Z

Link: CVE-2026-1225

cve-icon Vulnrichment

Updated: 2026-01-22T14:14:14.793Z

cve-icon NVD

Status : Received

Published: 2026-01-22T10:16:07.693

Modified: 2026-01-22T10:16:07.693

Link: CVE-2026-1225

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses