CVE catalog

CVE-2026-104721

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

[CVE catalog]

Severity: Medium · CVSS 6.3CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:P/AU:N/R:X/V:X/RE:M/U:Green
Published: Oct 2, 2026, 1:21:59 PM UTC
Updated: Oct 2, 2026, 2:17:10 PM UTC
Source: [NVD] · [CVE record]
EPSS: 0.33% · Oct 27, 2026

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.

Vulnerable and fixed packages

Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.

Distribution	Package	Release	Version	Status
Debian	logback	sid	`1:1.6.3-3`	vulnerable
Debian	logback	forky	`1:1.6.3-3`	vulnerable
Debian	logback	trixie	`1:1.2.11-6`	vulnerable
Debian	logback	bookworm	`1:1.2.11-3`	vulnerable
Opensuse	logback	tumbleweed	`1.6.5-2.1`	fixed

Fixed-version evidence

Distribution	Package	Type	Release	Fixed version	Urgency	Origin	Bugs
Debian	logback	source	sid	`(unfixed)`	not yet assigned	Not reported	[1149909]
Debian	logback	source	forky	`(unfixed)`	not yet assigned	Not reported	[1149909]
Debian	logback	source	trixie	`(unfixed)`	not yet assigned	Not reported	[1149909]
Debian	logback	source	bookworm	`(unfixed)`	not yet assigned	Not reported	[1149909]
Opensuse	logback	rpm	tumbleweed	`1.6.5-2.1`	Not reported	OPENSUSE-SU-2026:11985-1	Not reported

[Debian bug #1149909]

Notes

[trixie] logback: Minor issue

OpenFactory catalog packages

[Debian 12 (Bookworm)]

[liblogback-java]Affected
Source package: [logback]
Details (2)
- 1:1.2.11-3 · all · bookworm
  Affected
  nvd · logback · debian · bookworm; nvd · logback · debian · 12
- 1:1.2.11-3 · all · bookworm
  Affected
  nvd · logback · debian · bookworm; nvd · logback · debian · 12
[liblogback-java-doc]Affected
Source package: [logback]
Details (2)
- 1:1.2.11-3 · all · bookworm
  Affected
  nvd · logback · debian · bookworm; nvd · logback · debian · 12
- 1:1.2.11-3 · all · bookworm
  Affected
  nvd · logback · debian · bookworm; nvd · logback · debian · 12

[Debian 13 (Trixie)]

[liblogback-java]Affected
Source package: [logback]
Details (2)
- 1:1.2.11-6 · all · trixie
  Affected
  nvd · logback · debian · 13
- 1:1.2.11-6 · all · trixie
  Affected
  nvd · logback · debian · 13

[openSUSE Tumbleweed]

[logback]Affected
Source package: [logback]
Details (1)
- 1.6.0-1.1 · noarch · tumbleweed
  Affected · Fixed: 1.6.5-2.1
  nvd · logback · opensuse · tumbleweed
[logback-access]Unknown
Source package: [logback]
Details (1)
- 1.6.0-1.1 · noarch · tumbleweed
  Unknown · Fixed: 1.6.5-2.1
  Version impact unknown
  nvd · logback · opensuse · tumbleweed
[logback-examples]Unknown
Source package: [logback]
Details (1)
- 1.6.0-1.1 · noarch · tumbleweed
  Unknown · Fixed: 1.6.5-2.1
  Version impact unknown
  nvd · logback · opensuse · tumbleweed
[logback-javadoc]Unknown
Source package: [logback]
Details (1)
- 1.6.0-1.1 · noarch · tumbleweed
  Unknown · Fixed: 1.6.5-2.1
  Version impact unknown
  nvd · logback · opensuse · tumbleweed

Observed: Oct 23, 2026, 7:46:39 PM UTC

References

[Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX]