CVE-2026-1225

Malicious logback.xml configuration file allows instantiation of arbitrary classes

LOW
1.8
CVSS Score
Published: January 22, 2026 at 09:24 AM UTC
Updated: June 17, 2026 at 10:15 AM UTC
1 product affected across 1 vendorLogback-core

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Severity
LOW1.8
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

0.9.20 ≤ v ≤ 1.5.240.9.20
Vendor states this is fixed in 1.5.25 (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

References (1)

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

1.8LOWNCSC.ch
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-20

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