CVE-2026-19880: Qos.ch Sarl Logback-Classic

Medium severity, CVSS 6.3. EPSS: 0.3% chance of exploitation in the next 30 days.

Path-traversal vulnerability in QOS.CH Sarl Logback-classic on Java (logback-classic module) allows path-traversal vulnerability. More specifically, an MDC-based discriminator value flows unsanitized into a nested FileAppender path, letting an attacker who influences that MDC value (e.g. via an HTTP header) create and append log files outside the intended directory. This issue affects Logback-classic: from 0.9.14 through 1.6.2.

Affected products

• Qos.ch Sarl Logback-Classic: from 0.9.14, up to and including 1.6.2

Published 2026-08-14. Last modified 2026-08-26.