Input validation error in Logback - CVE-2026-1225
Published: March 10, 2026
Vulnerability identifier: #VU123671
CSH Severity: Low
CVSS v4.0: 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/E:U/U:Clear
CVE-ID: CVE-2026-1225
CWE-ID: CWE-20
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vendor: QOS.ch
Affected software:
Logback
Logback
Detailed vulnerability description
The vulnerability allows a local privileged user to perform a denial of service (DoS) attack.
The vulnerability exists due to insufficient validation of user-supplied input. A local privileged user can 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.
How to mitigate CVE-2026-1225
Install updates from vendor's website.