CVE intelligence and bounded remediation

CVE-2025-27409 — Joplin is a free, open source note taking and to-do application, which can handle a large number of notes organised into notebooks

High CVSS 7.5

Joplin is a free, open source note taking and to-do application, which can handle a large number of notes organised into notebooks. Prior to version 3.3.3, path traversal is possible in Joplin Server if static file path starts with `css/pluginAssets` or `js/pluginAssets`. The `findLocalFile` function in the `default route` calls `localFileFromUrl` to check for special `pluginAssets` paths. If the function returns a path, the result is returned directly, without checking for path traversal. The vulnerability allows attackers to read files outside the intended directories. This issue has been patched in version 3.3.3.

Severity
High
CVSS
7.5 (3.1)
Published
2025-04-30
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-22

Affected products

  • joplin_project / joplin

Matched remediation archetype

Path traversal, unsafe upload, and file handling

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Check exposure

  • Trace untrusted filenames, archive entries, URLs, and path segments into read, write, include, extraction, and upload operations.
  • Identify filesystem roots, mount permissions, symbolic-link behavior, archive handling, and whether uploaded content is web-accessible or executable.
  • Review canonicalization and containment checks across supported operating systems and storage backends.

Remediate safely

  • Generate server-side storage identifiers and resolve paths beneath a fixed root using filesystem-aware containment checks.
  • Reject absolute, parent-relative, alternate-separator, device, link, and archive entries that escape the intended root.
  • Store uploads outside executable or served paths, validate type and size, and use private atomic temporary files.

Authoritative sources

Complete CVE record and remediation plan

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