Vulnerability · Published Oct 5, 2026 · Assigned by GitHub_M
CVE-2026-105784Joplin whiteboard card rendering allows CSS injection into application chrome
Medium 4.6
In plain English
A medium-severity cross-site scripting in joplin from laurent22. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 16% of all known vulnerabilities).
Official description
Joplin is an open source note-taking and to-do application that organises notes and lists into notebooks. Prior to 3.7.13, selecting a note containing a jsoncanvas fence causes the whiteboard text and file-node components in packages/app-desktop/gui/NoteEditor/NoteBody/WhiteboardEditor/nodes/TextNode.tsx and packages/app-desktop/gui/NoteEditor/NoteBody/WhiteboardEditor/nodes/FileNode.tsx to render card content with the full Markdown renderer. The components insert the resulting HTML into the main application document through dangerouslySetInnerHTML. A malicious note can inject style elements and remote CSS imports that modify trusted application chrome, signal when the note is opened, and potentially disclose exposed attribute values. Content Security Policy blocks inline script execution, so the supported impact is CSS injection and UI redressing rather than code execution. This issue is fixed in version 3.7.13.
Affected products (as reported)
Weakness: CWE-79 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N
References
- https://github.com/laurent22/joplin/security/advisories/GHSA-6h4j-86j4-x4q4 x_refsource_CONFIRM
- https://github.com/laurent22/joplin/pull/16275 x_refsource_MISC
- https://github.com/laurent22/joplin/commit/7fb9ec93e47cec39a548a76e03d7ad660ca0f123 x_refsource_MISC
- https://github.com/laurent22/joplin/releases/tag/v3.7.13 x_refsource_MISC