All vulnerabilities
CVE-2026-104721

Logback-classic: Logback: Incomplete protection against CVE-2026-19880

QOS.CH Sarl Logback-classic
Open in ThreatlineRecord JSON
CVSS
6.3Medium
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.33%Chance of exploitation activity in the next 30 days, higher than 25% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed inNone listedNo source names a fixed version yet
Published2 Oct 2026Updated 2 Oct 2026CVE List

What fixes it

No source in this snapshot names a fixed version.

Description

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 1.6.4.  This vulnerability is similar to CVE-2026-19880 but involves other attack techniques.

Text from CVE List

Affected versions 2

  • Logback-classicaffected: 0.9.14 through 1.6.4CVE List
  • Logback-classicunaffected: 1.6.5CVE List

References 1