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).

Severity (CVSS 3.1)4.6Medium
Exploit odds (30 days)0.2%top 84.3% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known

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)

VendorProductVersions
laurent22 joplin < 3.7.13

Weakness: CWE-79 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N

References