CVE-2026-19880

Summary

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 Software

VendorProductVersion RangeStatus
QOS.CH SarlLogback-classic0.9.14 <= 1.6.2affected
QOS.CH SarlLogback-classic1.6.3unaffected

Weaknesses

  • CWE-22: CWE-22

Workarounds

Update to logack version 1.6.3 or later. This vulnerability requires SiftingAppender to be active as well as unsanitized data provided by an attacker that MDCDiscriminator makes use of.

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

References