CVE-2026-104721
Logback: Incomplete protection against CVE-2026-19880
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.
INFO
Published Date :
Oct. 2, 2026, 1:21 p.m.
Last Modified :
Oct. 2, 2026, 1:21 p.m.
Remotely Exploit :
Yes !
Source :
NCSC.ch
Affected Products
The following products are affected by CVE-2026-104721
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 4.0 | MEDIUM | 455daabc-a392-441d-aa46-37d35189897c |
Solution
- Update Logback-classic to version 1.6.5 or later.
- Sanitize MDC values before using them in file paths.
- Restrict access to log directories.
- Monitor log file creation activities.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-104721 vulnerability anywhere in the article.